I have galaxy note 20 ultra 5g (Model: SM-N986B/DS). I'm using it for a couple of months. The problem I'm facing is that when I use any app and I switch off the screen while using the app, after I switch on the screen, it shows me the home screen, not the app. Then I go to recent apps and then select the last app, when that app opens it starts from the beginning, not from there where i left it last time. Same issue having in Samsung Media Library/Video Player and other apps. Some times it keeps in memory, but most of the time not.
Please try to fix it by software update.