diff --git a/.changeset/healthy-rabbits-sip.md b/.changeset/healthy-rabbits-sip.md
new file mode 100644
index 0000000000000..5207f42462854
--- /dev/null
+++ b/.changeset/healthy-rabbits-sip.md
@@ -0,0 +1,5 @@
+---
+"@rocket.chat/meteor": patch
+---
+
+Fixes an issue where `user-agent` is not properly extracted from the DDP connection headers
diff --git a/apps/meteor/ee/server/lib/deviceManagement/session.ts b/apps/meteor/ee/server/lib/deviceManagement/session.ts
index 7d68f89942cda..c5b286c9dff2c 100644
--- a/apps/meteor/ee/server/lib/deviceManagement/session.ts
+++ b/apps/meteor/ee/server/lib/deviceManagement/session.ts
@@ -66,7 +66,12 @@ export const listenSessionLogin = () => {
 			username,
 			emails: [{ address: email }],
 		} = user;
-		const { browser, os, device, cpu, app } = await uaParser(connection.httpHeaders['user-agent']);
+
+		const userAgentString =
+			connection.httpHeaders instanceof Headers
+				? (connection.httpHeaders.get('user-agent') ?? '')
+				: (connection.httpHeaders['user-agent'] ?? '');
+		const { browser, os, device, cpu, app } = await uaParser(userAgentString);
 
 		const mailData = {
 			name,