Navigation mesh is wrong in VR.

I have a house with two floors in UE4. On both floors the navigation mesh shows up higher than the actual floor mesh is (I’ve just applied a box collision to the floor within the editor).

The player starts at the correct height but as soon as they teleport it sends the player higher than they actually are. It’s like the teleporter doesn’t recognise the targets actual position.

My current fix is move the box collision much lower than it should be to accommodate for the shift in height.

This isn’t a great idea though as its not completely accurate, does anyone know whats going on with this?