That's just how gravity and balance wheels get on. The idea of the tourbillon is to counteract this by rotating the balance constantly. Doesn't necessarily work though. The best solution is just to make the movement more accurate (with finer adjustment, amagnetic balance springs etc).
Yeah figured. Just weird that it affects that movement so badly. The other autos I have - Zenith / Seiko / Junghans don’t seem to mind being left flat, face up so much.
Tested this last night. Yeah, stored crown down it doesn't shit the bed like it would if stored flat. Curious.