Some system settings are not saved. Settings that were set in the ‘LiveDisplay’-menu are not applied and are back to their original values after the restart.
The previously deactivated fast charging is also set back to standard (=active) after the restart.
Does anyone have an idea how to correct this “error”?
If you own an S9+ (like me) or an S9, you are not alone : S9 "starlte": some settings are reset after phone reboot (#4180) · Issues · e / Backlog · GitLab
Same problem here in French "Bug" démarrage Samsung Galaxy S9
Translated with deepl it looks like this:
Hello everyone,
Just a quick question for those of you who own a Samsung Galaxy S9 (android 10 /dev V1.1) :
When booting or restarting, I noticed two minor malfunctions. Namely:
the fast battery charge option is automatically activated even when it was initially disabled.
the proximity sensor to move the hand in front of the screen (in order to display the time for example without "waking up" the phone completely) does not work anymore. I have to reactivate it every time.
The notification sound is disabled when it was not before (phone in vibrate mode but with notification sound not linked to the phone sound). I have to activate it manually.
Have you also had this kind of small problem? It’s not a big deal, but it’s just a matter of getting your feedback.
Thanks 
On my S9+, I suffer the 1st (fast battery charge) but not the 3rd (notif. sound) ; as for the 2nd (proximity sensor) … don’t care and don’t know how to check, no use for me.