This only started 2 days ago but it is infuriating and making me consider a factory reset. Regardless on whether silent, vibrate or sound notifications is selected, a notification chime will always play when a notification comes through. This also bypasses do not disturb mode, making me even more confused. Very likely a glitch and interrupts all videos and such making it extremely annoying, and cannot find any other examples of this online either. Please tell me if i am being stupid to fix this.
I'm having the same issue. It's infuriating.
Temporary solution is to disable the "Google" app completely. This affects Google Assistant but will stop the constant notifications.
EDIT: Disabling Google in Notification Access also fixes the issue.