Audio not working om start VR game

Hi all,
i created a vr game and experience a strange audio problem. When i make a build and start the gane, audio is not working. I have to left mouse click to activate it.

Because the game plays in a vr environment it is a bit problemetic to fix.

I tested this game on multiple computers, some does not have this issue, others sometimes, and one system all the time.

Does anyone has any idea how to solve this ? I use ue4 version 4.22.2 and the hp reverb as a VR headset