MOBILE - Game freezes when coming back from inactivity screen turn off

Platform, device version and operating system:
Android, S8
Screenshot or image:

What you were expecting to happen, and what actually happened:
It happens on each game screen. When going back to game from screen turned off - I can do an action for 1-2s, then game freezes for about 1-2 minutes. Sometimes android displays screen whether to turn off game or wait. It freezes whole mobile - no buttons work, I cannot turn off screen, cannot minimalise game. I would expect not to get whole mobile frozen.

How often does this happen? When did it begin happening?
It happens almost every time I get back to game from display turned off due to inactivity. I think it started happening about 1-2 months ago.

Steps to make it happen again
Play a battle, do nothing, wait till screen turns off due to inactivity, then get back to the game. It does not happen every time, but it happens pretty often to me.