Whenever I turn my Note 20 Ultra 5G back on in a morning (it's off overnight to charge, the charger being on a timer) it always forgets that I've set Nova Launcher as the default Home app and I need to set it again in the Settings and then restart the phone.
I've read on reddit others are having the same problem, it's not just nova launcher is others to. As soon as the phone reboots its forgetting the launcher set. Haven't read a fix but looks like could be update. So needs fixing. You could always go on reddit and look it up. You might read something I missed.