I had something like this happen a few months ago. I was in a parking lot and took a corner too tight and rode up on a curb and then dropped off it, which caused my car to think one of the seatbelts wasn't clicked.
I spent the next several months ignoring the dinging until I did the same exact thing in another parking lot, which fixed it. Good ol' percussive maintenance.
I was going to complain in the comments that the article doesn't mention anything about lockdown mode on iOS, but thankfully this eff one does. Thanks for sharing a superior article!