Navigation mesh problem with VR template (4.26.1)

Greetings. I am using the VR template (4.26.1) and the motion controller map. Although that I have set up the Nav Mesh Bounds properly (I think…) I am not able walk on the cubes that you see in the attached photo. As you can see the nav mesh is extended on the cubes. Each cube is an actor BP with a static mesh (ue4 starter content asset) and some code in it.

Does anyone know what’s wrong with this? Are there any limitations for the nav mesh bounds volume? I mean does it work on actor BPs?
Thank you in advance.

I found a solution. It’s not what I was looking for but it works so If anyone is interested…its described in this video: