I got a version of this alert for the first time on a OnePlus 9 last week whilst using my phone on a long motorcycle trip. It also suggested there might be a f

I got a version of this alert for the first time on a OnePlus 9 last week whilst using my phone on a long motorcycle trip. It also suggested there might be a foreign object in the port. Curiously it wasn't raining at the time and had been charging ok for an hour or so. It was the only time I saw this error during the 5,000 km trip - including times when it was raining hard. Unplugging and replugging the (2 amp) lead did nothing, but leaving it unplugged for ~30 mins seemed to fix it.