Codex becomes extremely slow and causes severe UI lag when working with many files

Jal: > It feels like some resources may not be properly released. Lag during long AI sessions is not always caused by a single process. On my Windows system, it is common for an AI tool to leave one or more long-running processes active after they should have been terminated. When this happens, manually stopping those processes often restores normal system performance. That said, the cause is not always related to the AI itself. Other background processes may also contribute to the slowdown. The practical approach is to use standard diagnostic methods—such as checking running processes and resource usage—to identify the root cause, whether it originates from the AI tool or from another application.