VR preview different behaviour from Desktop view


I am trying to simulate 2 floor office building.
Players start on the 1st floor in UE4 file.
After starting in Desktop mode it works fine.
Once started in VR mode player is in the 2nd floor and I can not get to the 1st one. Floor has a standard opening.
Straight stairs modeled using blocking volumes.
What could be wrong?

Thank you for your support