EDIT: This issue has mostly just disappeared by itself and I don't seem to get it anymore. I found that powering of your device for a few hours (such as overnight) then turning it back on gets rid of this issue, and also try sticking to the phones original charging cable. You might also find what I wrote below useful if this issue is still happening for you:
I sometimes randomly experience this as well, before it was just the usb connection notification but now the screen won't turn of either (it just keeps returning to the lock screen and won't go black). I've tried developer settings, cleaning the charging port and other things to at least stop the annoying notifications but nothing worked permanently. However if you are still experiencing the screen not turning off, then I found a temporary fix and I think it should work each time.
FIX: connect a different (USB C) cable to the charging port but don't plug the other end in or turn it on. Just plug it in and out of the port a few times and this will allow the screen to turn off. once it turns off you can disconnect the cable. make sure the cable is different from the one you usually use to charge.
As of right now, I still get the usb connection notifications and the charging time can be longer/shorter battery life than usual. It could be a hardware issue but I'm certain it's to do with a software bug with the charging port.
