If I remember right on my Android 10 Xiaomi Mi Max 3 I had to find and manually allow display over other apps. It was in :-
Settings/Passwords & security/Privacy/Special app access/Display over other apps.
EDIT: I think I'm wrong, it was :-
Settings -> Apps -> Permissions -> Other Permissions -> B4A-Bridge and enable "Display pop-up windows while running in the background"
needed to to install an app if B4A-Bridge was not in the foreground.
If I remember right on my Android 10 Xiaomi Mi Max 3 I had to find and manually allow display over other apps. It was in :-
Settings/Passwords & security/Privacy/Special app access/Display over other apps.
EDIT: I think I'm wrong, it was :-
Settings -> Apps -> Permissions -> Other Permissions -> B4A-Bridge and enable "Display pop-up windows while running in the background"
needed to to install an app if B4A-Bridge was not in the foreground.