The scariest moment in development was when SwiftUI re-renders killed my game timer

Had a bug where the mission timer would randomly reset because SwiftUI's state management was triggering re-renders that reinitilized the timer. Took me days to track down because the timer worked perfectly in isolation -- it only broke when other UI elements updated. Ended up replacing Combine observers with a simple polling timer. Sometimes the "modern" approach isn't the right one. What framework battles have you fought?