Issue Description:
Trainers using app versions earlier than 0.417 may experience an issue where a nearby Gym disappears from the map after collecting a Stamp Rally stamp.

Status:
Fixed in app version 0.417. Please update to app version 0.417 or later to avoid this issue.

Workaround:
If you encounter this issue, please relaunch the app. The Gym should appear again after restarting the game.