Dear Klaus,
I found two of the similar issues reported in the forum so I answered them both in case somebody finds one or another.
The solution for the issue, but I don't know how this will affect 360 video playback:
when you open the inappbrowser you must set the option "mediaPlaybackRequiresUserAction=yes".
I have Cordova 9, latest inappbrowser.
I'm opening a WebVr scene with hotspots, everything works as expected, but once you are clicking on the button to Enter VR, first the krpano settings panel is showing up because it not recognizes my iPhone 11, then after 2-3 sec the native audio player overlays the entire VR.
This issue must be related with to the new inappbrowser > 1.5.5^dev and present in both 1.19 and 1.20 krpano.
I cannot post an example because of privacy contract with Audi AG.
http://max.myvalido.com/1.png
http://max.myvalido.com/2.png
http://max.myvalido.com/3.png