I mow lawns daily and stream xm tunes to Bose buds while doing so. Today I get to my last lawn and open my S21 Ultra to start the streaming service to find I have zero screen. I hop back into the truck and mess with the phone a bit and then gave up. I mowed my last lawn and came home and put the phone on the charger. I'm thinking either the phone got too hot or did not charge over night and is out of power. On the charger it's status is displayed as 86% charged and 22 minutes until fully charged. I'm instantly put at ease knowing the phone is functional. I let if fully charge and then removed it from the charger. It asked for my login and I was into the phone. The screen was barely lit. I go into setting and see that the brightness slider is all the way down. It's no wonder I couldn't see the screen in the daylight. I brightened the screen and then found a number of settings changed. I was in light mode instead of dark, I had a nav bar at the bottom of the screen and I always use swipe, and there weren't any app badge numbers on my notifications. That's the settings that I have so far discovered were changed. I'm hoping that my phone just jumped around in my pocket just right (OR WRONG) and changed those settings. If it was another culprit.. I'm in for some kind of fun finding it.