iPad turns black but does not turn off

Dear Apple

When I use youtube or a game on my ipad it works but after 2 or 3 minutes it randomly goes black but it does not turn off.

My YouTube video will continue if I do not turn my iPad off

when I turn it off when it's in that black screen its getting the normal black screen of a turned off iPad. Pls help because its very annoying and frustrating because it also happends at school.

greats Max Burgers