Up until UI 3, my Note 10+ 5G would suggested my most likely app when I pressed the app switcher button, eg when in my crossword app, pressing it would put my anagram solver first in the list of recently used apps even if I hadn't used it for ages. I really liked this feature, but since the update it doesn't do it any more. Is there a toggle in settings to turn it back on?
depending on how long you have had U.I 3 installed, it will probably be learning your mostly used apps again. if it's been less than a month give it a little more time. I turn this off, and there doesn't seem to be any other options other than to toggle on or off. Incase you don't know already, I will screenshot the way to look for yourself, Recent >> top right 3 dots >> Settings.