It's important that you specify which version of non-root you have so people can respond accordingly. Personally, I have android 10 on an LG G8x and non-root version 14.21.54 (old version) and picture-in-picture works (the name of the little preview window). Haven't tried newer versions but maybe someone can respond when you specify which app version you have specificallyHello.. I'm using unroot YouTube vanced on redmi note 9.
Why picture in picture seems to dissappear?
On my old phone I used to have this mini player playing on screen when I minimised the app, I still can watch my YouTube video while doing the other thing on my phone like chatting, scroll through Instagram and etc. But I don't have it now.
I set it on from settings-general-picture-in-picture, I set it to allow the special app access for picture in picture from my phone setting as well , still can't have it.
Does this feature doesn't work on android 10?