Auto battle question

Auto grind on phone question

Hi everyone I'm using an old Huawei mate 20x with emui 12 At work I would usually leave my phone to auto grind gacha events or even overnight due to how long it takes usually

However noticed recently that my phone doesn't do auto battle anymore. Previously when I ran battles it would grind through the amount of battles I set

Now the screen darkens and it will remain off. When I go back into the game it remains on the first battle unless I manually keep the phone screen on. It doesn't even seem to be working through the game. Why is that. I tried tweaking settings on my phone so it doesn't auto go to sleep but it's the same issue regardless.