Chosen Solution
My phone screen keeps turning itself on and displaying an alert that says please turn your handset off/ on and then two options at the bottom that say ok or cancel and at the top left there’s a back option. It doesn’t look very official and I don’t know why my phone would be giving me that alert. Next time it happens I’ll screenshot and upload it. Just a bit worried I’d been hacked and if I have what to do. Popped up twice- once when I was watching something and once when my screen was off it turned itself on to show it.
You most likely have some apps running in the background that have pop ups. Something like battey saver app or something Think about what app you recently downloaded when it started.