diff --git a/src/Directory.Build.props b/src/Directory.Build.props
index 7a1712b7..499b69b6 100644
--- a/src/Directory.Build.props
+++ b/src/Directory.Build.props
@@ -1,4 +1,5 @@
 <Project>
+
     <PropertyGroup>
         <TargetFramework>net9.0</TargetFramework>
         <RepositoryUrl>https://github.com/arcenox-co/TickerQ</RepositoryUrl>
@@ -8,7 +9,7 @@
         <PackageIcon>icon.jpg</PackageIcon>
         <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
         <Version>9.1.0</Version>
-        <DotNetVersion>[9.0.0,10.0.0)</DotNetVersion>
+        <DotNetVersion>[10.0.0,11.0.0)</DotNetVersion>
         <LangVersion>default</LangVersion>
     </PropertyGroup>
 
@@ -17,5 +18,4 @@
     </ItemGroup>
 
     <Import Project="$([MSBuild]::GetPathOfFileAbove('Directory.Build.props', '$(MSBuildThisFileDirectory)../'))" />
-
 </Project>
diff --git a/src/TickerQ.EntityFrameworkCore/Infrastructure/BasePersistenceProvider.cs b/src/TickerQ.EntityFrameworkCore/Infrastructure/BasePersistenceProvider.cs
index b4d0fd49..f81ecb53 100644
--- a/src/TickerQ.EntityFrameworkCore/Infrastructure/BasePersistenceProvider.cs
+++ b/src/TickerQ.EntityFrameworkCore/Infrastructure/BasePersistenceProvider.cs
@@ -103,9 +103,10 @@ public async Task ReleaseAcquiredTimeTickers(Guid[] timeTickerIds, CancellationT
         await using var dbContext = await DbContextFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);;
         var now = _clock.UtcNow;
             
-        var baseQuery = timeTickerIds.Length == 0
+        var idList = timeTickerIds.ToList();
+        var baseQuery = idList.Count == 0
             ? dbContext.Set<TTimeTicker>()
-            : dbContext.Set<TTimeTicker>().Where(x => timeTickerIds.Contains(x.Id));
+            : dbContext.Set<TTimeTicker>().Where(x => idList.Contains(x.Id));
             
         await baseQuery
             .WhereCanAcquire(_lockHolder)
@@ -127,9 +128,15 @@ public async Task<int> UpdateTimeTicker(InternalFunctionContext functionContexts
     public async Task UpdateTimeTickersWithUnifiedContext(Guid[] timeTickerIds, InternalFunctionContext functionContext, CancellationToken cancellationToken = default)
     {
         await using var dbContext = await DbContextFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);;
+        var idList = timeTickerIds.ToList();
         await dbContext.Set<TTimeTicker>()
+<<<<<<< HEAD
             .Where(x => timeTickerIds.Contains(x.Id))
             .ExecuteUpdateAsync(MappingExtensions.UpdateTimeTicker<TTimeTicker>(functionContext, _clock.UtcNow), cancellationToken).ConfigureAwait(false);
+=======
+            .Where(x => idList.Contains(x.Id))
+            .ExecuteUpdateAsync(setter => setter.UpdateTimeTicker<TTimeTicker>(functionContext, _clock.UtcNow), cancellationToken).ConfigureAwait(false);
+>>>>>>> 39b9b90 (Fix .NET 9+ EF Core query failures caused by ReadOnlySpan array.Contains() (#574))
     }
         
     public async Task<TimeTickerEntity[]> GetEarliestTimeTickers(CancellationToken cancellationToken)
@@ -214,10 +221,11 @@ public async Task<TimeTickerEntity[]> AcquireImmediateTimeTickersAsync(Guid[] id
 
         await using var dbContext = await DbContextFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
         var now = _clock.UtcNow;
+        var idList = ids.ToList();
 
         // Acquire and mark InProgress in a single update
         var affected = await dbContext.Set<TTimeTicker>()
-            .Where(x => ids.Contains(x.Id))
+            .Where(x => idList.Contains(x.Id))
             .WhereCanAcquire(_lockHolder)
             .ExecuteUpdateAsync(setter => setter
                 .SetProperty(x => x.LockHolder, _lockHolder)
@@ -232,7 +240,7 @@ public async Task<TimeTickerEntity[]> AcquireImmediateTimeTickersAsync(Guid[] id
         // Return the acquired tickers for immediate execution, with children
         return await dbContext.Set<TTimeTicker>()
             .AsNoTracking()
-            .Where(x => ids.Contains(x.Id) && x.LockHolder == _lockHolder && x.Status == TickerStatus.InProgress)
+            .Where(x => idList.Contains(x.Id) && x.LockHolder == _lockHolder && x.Status == TickerStatus.InProgress)
             .Include(x => x.Children.Where(y => y.ExecutionTime == null))
             .Select(MappingExtensions.ForQueueTimeTickers<TTimeTicker>())
             .ToArrayAsync(cancellationToken)
@@ -245,7 +253,7 @@ public async Task MigrateDefinedCronTickers((string Function, string Expression)
         await using var dbContext = await DbContextFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
         var now = _clock.UtcNow;
 
-        var functions = cronTickers.Select(x => x.Function).ToArray();
+        var functions = cronTickers.Select(x => x.Function).ToList();
         var cronSet = dbContext.Set<TCronTicker>();
 
         // Build the complete set of registered function names to detect orphaned tickers.
@@ -262,16 +270,17 @@ public async Task MigrateDefinedCronTickers((string Function, string Expression)
             .ToArrayAsync(cancellationToken)
             .ConfigureAwait(false);
 
-        if (orphanedCron.Length > 0)
+        var orphanedCronList = orphanedCron.ToList();
+        if (orphanedCronList.Count > 0)
         {
             // Delete related occurrences first (if any), then the cron tickers
             await dbContext.Set<CronTickerOccurrenceEntity<TCronTicker>>()
-                .Where(o => orphanedCron.Contains(o.CronTickerId))
+                .Where(o => orphanedCronList.Contains(o.CronTickerId))
                 .ExecuteDeleteAsync(cancellationToken)
                 .ConfigureAwait(false);
 
             await cronSet
-                .Where(c => orphanedCron.Contains(c.Id))
+                .Where(c => orphanedCronList.Contains(c.Id))
                 .ExecuteDeleteAsync(cancellationToken)
                 .ConfigureAwait(false);
         }
@@ -421,9 +430,10 @@ public async Task ReleaseAcquiredCronTickerOccurrences(Guid[] occurrenceIds, Can
         var now = _clock.UtcNow;
         await using var dbContext = await DbContextFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);;
             
-        var baseQuery = occurrenceIds.Length == 0 
-            ? dbContext.Set<CronTickerOccurrenceEntity<TCronTicker>>() 
-            : dbContext.Set<CronTickerOccurrenceEntity<TCronTicker>>().Where(x => occurrenceIds.Contains(x.Id));
+        var idList = occurrenceIds.ToList();
+        var baseQuery = idList.Count == 0
+            ? dbContext.Set<CronTickerOccurrenceEntity<TCronTicker>>()
+            : dbContext.Set<CronTickerOccurrenceEntity<TCronTicker>>().Where(x => idList.Contains(x.Id));
            
         await baseQuery
             .WhereCanAcquire(_lockHolder)
@@ -525,11 +535,12 @@ public async Task<CronTickerOccurrenceEntity<TCronTicker>> GetEarliestAvailableC
     {
         var now = _clock.UtcNow;
         var mainSchedulerThreshold = now.AddSeconds(-1);
+        var idList = ids.ToList();
         await using var dbContext = await DbContextFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);;
         return await dbContext.Set<CronTickerOccurrenceEntity<TCronTicker>>()
             .AsNoTracking()
             .Include(x => x.CronTicker)
-            .Where(x => ids.Contains(x.CronTickerId))
+            .Where(x => idList.Contains(x.CronTickerId))
             .Where(x => x.ExecutionTime >= mainSchedulerThreshold)  // Only items within the 1-second main scheduler window
             .WhereCanAcquire(_lockHolder)
             .OrderBy(x => x.ExecutionTime)
@@ -554,9 +565,15 @@ public async Task UpdateCronTickerOccurrencesWithUnifiedContext(Guid[] cronOccur
         CancellationToken cancellationToken = default)
     {
         await using var dbContext = await DbContextFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);;
+        var idList = cronOccurrenceIds.ToList();
         await dbContext.Set<CronTickerOccurrenceEntity<TCronTicker>>()
+<<<<<<< HEAD
             .Where(x => cronOccurrenceIds.Contains(x.Id))
             .ExecuteUpdateAsync(MappingExtensions.UpdateCronTickerOccurrence<TCronTicker>(functionContext), cancellationToken)
+=======
+            .Where(x => idList.Contains(x.Id))
+            .ExecuteUpdateAsync(setter => setter.UpdateCronTickerOccurrence<TCronTicker>(functionContext), cancellationToken)
+>>>>>>> 39b9b90 (Fix .NET 9+ EF Core query failures caused by ReadOnlySpan array.Contains() (#574))
             .ConfigureAwait(false);
     }
     
diff --git a/src/TickerQ.EntityFrameworkCore/Infrastructure/TickerEFCorePersistenceProvider.cs b/src/TickerQ.EntityFrameworkCore/Infrastructure/TickerEFCorePersistenceProvider.cs
index c4b0cc11..2e3b1328 100644
--- a/src/TickerQ.EntityFrameworkCore/Infrastructure/TickerEFCorePersistenceProvider.cs
+++ b/src/TickerQ.EntityFrameworkCore/Infrastructure/TickerEFCorePersistenceProvider.cs
@@ -101,10 +101,11 @@ public async Task<int> RemoveTimeTickers(Guid[] timeTickerIds, CancellationToken
             await using var dbContext = await DbContextFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);;
             
             // Load the entities to be deleted (including children for cascade delete)
+            var idList = timeTickerIds.ToList();
             var tickersToDelete = await dbContext.Set<TTimeTicker>()
                 .Include(x => x.Children)
                 .ThenInclude(x => x.Children) // Include grandchildren if needed
-                .Where(x => timeTickerIds.Contains(x.Id))
+                .Where(x => idList.Contains(x.Id))
                 .ToListAsync(cancellationToken)
                 .ConfigureAwait(false);
             
@@ -189,7 +190,8 @@ public async Task<int> UpdateCronTickers(TCronTicker[] cronTickers, Cancellation
         public async Task<int> RemoveCronTickers(Guid[] cronTickerIds, CancellationToken cancellationToken)
         {
             await using var dbContext = await DbContextFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
-            var result = await dbContext.Set<TCronTicker>().Where(x => cronTickerIds.Contains(x.Id))
+            var idList = cronTickerIds.ToList();
+            var result = await dbContext.Set<TCronTicker>().Where(x => idList.Contains(x.Id))
                 .ExecuteDeleteAsync(cancellationToken).ConfigureAwait(false);
             
             if(RedisContext.HasRedisConnection)
@@ -246,8 +248,9 @@ public async Task<int> InsertCronTickerOccurrences(CronTickerOccurrenceEntity<TC
         public async Task<int> RemoveCronTickerOccurrences(Guid[] cronTickerOccurrences, CancellationToken cancellationToken = default)
         {
             await using var dbContext = await DbContextFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
+            var idList = cronTickerOccurrences.ToList();
             return await dbContext.Set<CronTickerOccurrenceEntity<TCronTicker>>()
-                .Where(x => cronTickerOccurrences.Contains(x.Id))
+                .Where(x => idList.Contains(x.Id))
                 .ExecuteDeleteAsync(cancellationToken).ConfigureAwait(false);
         }
 
@@ -258,10 +261,11 @@ public async Task<CronTickerOccurrenceEntity<TCronTicker>[]> AcquireImmediateCro
 
             await using var dbContext = await DbContextFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
             var now = _clock.UtcNow;
+            var idList = occurrenceIds.ToList();
 
             // Only acquire occurrences that are acquirable (Idle/Queued and not locked by another node)
             var query = dbContext.Set<CronTickerOccurrenceEntity<TCronTicker>>()
-                .Where(x => occurrenceIds.Contains(x.Id))
+                .Where(x => idList.Contains(x.Id))
                 .WhereCanAcquire(_lockHolder);
 
             // Lock and mark InProgress
@@ -279,7 +283,7 @@ public async Task<CronTickerOccurrenceEntity<TCronTicker>[]> AcquireImmediateCro
             // Return acquired occurrences with CronTicker populated
             return await dbContext.Set<CronTickerOccurrenceEntity<TCronTicker>>()
                 .AsNoTracking()
-                .Where(x => occurrenceIds.Contains(x.Id) && x.LockHolder == _lockHolder && x.Status == TickerStatus.InProgress)
+                .Where(x => idList.Contains(x.Id) && x.LockHolder == _lockHolder && x.Status == TickerStatus.InProgress)
                 .Include(x => x.CronTicker)
                 .ToArrayAsync(cancellationToken)
                 .ConfigureAwait(false);