Animation loop stops playing correctly after long periods of time (4+ days)

I have a scene of a rotating prop with 1 animation associated with it. I have noticed after long periods of playback of a build, 4+ days, the animation playback falls apart. It doesn't play back at the expected rate, rather is is moving so slow you can't perceive it unless you mark the screen and come back in and hour. Has anyone else had issues with animation playback over days of a build running?