Not sure what to tell you. Nothing has changed in the last 2 months (i.e. no updates), so whatever it is, it's probably caused by and alleviated by something in-game.
It could be as simple as a hiccup when saving the position and rotation back to the database, which could be completely random.
But, hopefully with some experimentation (which I admit may take a long time), something can be determined, at least perhaps on how to alleviate it if it does happen.