"hey Google" triggers the assistant to open, even on the lock screen even though it's disabled.
If I toggle it on and off it'll actually stay off for a day or two but it always comes back. I'm on a Galaxy S20 Android 13 I believe.
It might be related to Samsung pushing apps/updates to your phone. I've seen them do similar on a galaxy tab before as well.
https://www.androidsage.com/2021/04/03/samsung-silently-installing-bloatware-apps-via-software-updates/
The stupid amount of bloat I couldn't uninstall is the reason I stopped using Samsung phones. Sure they are popular and decently priced, but Samsung is really showing how much they don't care about the user experience since they are on top.