Inspect the right state
Record the installed patch, city, in-game date and current activity. Note whether the slowdown occurs during interface changes, AI activity or a late-game simulation. A city name alone does not isolate the cause, and a different save is not a controlled comparison.
Make the decision
Retest the reported scenario after confirming the update is installed. If it improves, retain the conditions rather than declaring all stutters fixed. If it persists, reduce the reproduction to the specific window or task that shows the problem without deleting the campaign.
Verify the result
Submit the affected save and hardware details through the official reporting route. The archive does not promise a frame-rate gain, recommend an undocumented launch flag or label every performance symptom as the old Nuremberg bug.