diff --git a/agent/context_compressor.py b/agent/context_compressor.py
index ef40cbfafbd4..c69a438b8a90 100644
--- a/agent/context_compressor.py
+++ b/agent/context_compressor.py
@@ -297,6 +297,7 @@ def on_session_reset(self) -> None:
         self._last_summary_error = None
         self._last_compression_savings_pct = 100.0
         self._ineffective_compression_count = 0
+        self._summary_failure_cooldown_until = 0.0  # transient errors must not block a fresh session
 
     def update_model(
         self,