Camera switches off when sharing screen

Hey people, I am working on an Ipad and have problems with my camera.

When I share the screen - whiteboard, everything works fine.

But when I share the screen and open another file to present my team, my camera switches off as soon as I leave zoom and go to my home screen to open up a file.

Do you know how this can be solved, that I am still visible while sharing other files/ good notes etc?