Got this notification using an USB-C to HDMI adapter then unplugging it after use, TV still on, and then plugging a charger fires the “debris” notification.
Reboot solves this.
After some testing, this notification doesn’t come if I shut down the TV first (OLED TV, need to wait the antiburning feature to finish, which can take from 30s to 2mn after turning it off), waiting for the phone to kill the external display connection notification in top bar, then unplug the adapter.
There is no setting to manually trigger the disconnection of the HDMI over USB-C feature, either “brutal” disconnection with phone still having the “display out” notification active or waiting the TV goes to sleep then unplug “safely”.
I think this is a lack in the phone features, not being able to shut down the HDMI over USB-C connection manually, USB-C chip on the phone doesn’t like “brutal” disconnection and nowhere there is user manual that tells this.
However HDMI over USB-C is a very usefull feature.