Yeah, I made sure I'm not in gun sight mode. If I pause tracking, the leaning works but when the tracking is activated it seems to actively fight the leaning, resetting the view. Even when holding my head in the dead zone.
Ah well, I managed to find one company in our country that had trackir 5 on shelf (sold out almost everywhere with 8-12 weeks 'til resupply) so I'll be switching to that in a couple of days anyway. So I get the full 6DOF on tracking. It's one way to solve the problem