Did you try to playing 360/VR video in YouTube app on Android 9 ?
After upgraded to Android 9, it looks like 360 video playing is not working. I tried Samsung s8, Honor 9, Huawei p30 pro with same result.
It's playing like a normal video. But in the FaceBook app is playing 360 video correctly.
I try to reset the phone and reinstall the app but no success.
Do somebody have same issue ?