In galaxy a71 finger print icon disappears from the always on display every time

I have galaxy a71 while changing the phone I noticed that battery percentage level varies from the one in always on display and in the inside display

I got galaxy A71 few dayz bak the issue is with the slow phone dialer. If i try to dial a contact from my contact list, the dialer after dialing wakes up very slowly after 8 to 10 seconds as if it was in a long sleep. I have even cleared unnessary co...