i turned the collision on the desk to block so i could jump on top of it.
I can make the same behavior occur by taking a standard cube actor and changing the scale to 0.6, 0.6, 0.6 and placing it on the floor. Then playing without a Vive, just First Person using the engine, if i walk up against that cube and rotate using the mouse, I pop up on top of it. It happens in VR too, but the cube has to be way smaller so its not a big deal at all.