I would guess its some kind of per-frame movement delta interacting with local geometry to determine if you are moving 'enough' to cross the threshold...higher framerates mean a smaller measured movement delta and it may be under some threshold required to move through the door geometry...so its keeps setting you back 'in-place'. It may be some kind of attempt to prevent getting stuck in the doorway or something.

It would be interesting to see what happens if you are moving very slowly ( as in encumbered and walking ) vs. moving very quickly ( ie., under selos ).

The primary doorway this is a problem with is for Cindl's shop. It is impacting small and medium races. This is replicable 100% of the time.

We need to force the game to run at ~60FPS imo. Would solve this issue and some others.

forcing 60fps would fix some things like levitate bugs

do it