My Samsung Note 20 Ultra 5G it started with being hot-ish at the back, then I noticed that the screen is frozen when I want to press on an app amd tonight restarted alone twice . I am planning to go with my phone to be checked next week, but I was just curious of anyone else had the same issue?
Normally, issues you're describing happen if there are too many apps running in the background. It could be there is a technical issue so it does need to be checked but make sure you are using the battery and device care option in settings. Go through all the options to maximise your phone performance
One good example is the use of "auto restarts" in the automation section... it is good and healthy for the phone to be restarted every so often. Believe it or not, there are people out there who never turn their phones off at all... its on in the day and on over night on charge... this isn't good for the device.