I'm experiencing this too, tried booting into safe mode and changing permission but the screen overlay detected message still appears. This is weird
In my case i had the Side Panel switched on. I switched it off and the problem went away...
We all had to start somewhere
1- Is there a way to root the mobile without tripping Knox ? Version 5.0 or a later one
Not really. There are some rooting products out there that claim to not trip Knox, but all i have read said to stay away from ...
I think you're right. I got an OTA update just a few days ago and the problem started then
I am thinking you are about to experience sudden death, where the memory fails. It's what happened to mine before it died
But try re-flashing first. Use latest stock for your phone. Check Sammobile for the latest