This has happened on 2 of my Samsung Note 10+ phones. The phone has not got wet and don't see anything in the charging port. Strange.
This message also came up while the phone was charging.
I have tried restarting the phone to see if that cleared it but it did not.
The message reads:
"We have detected moisture or foreign material in your charging/USB port.
Check your charging/USB port for any foreign material such as dust or debris. To prevent damage to your phone, don't plug anything in until the charging port is clean, the moisture is gone, and the notification is cleared.
To dry the port, shake out any moisture, then wait for it to dry, which could take several hours. You can speed up drying by pointing a fan or dryer (cool air only) at the port.
In the meantime, you can charge your phone wirelessly."
Does anyone have a solution to fix this?
My phone is over a year old so is no longer under Samsung's warranty.
Possibly too late to help you but YES i just had this error today on waking up.
Tried all tricks available in the internet (except factory reset) to no avail.
Called the dealer. Told him there's no moisture nor dust in the port. He said moisture in tiny amounts can be produced even by Air Conditioning in a room or car.
Turns out, I had slept in a hotel room and put the AC to slightly humid state accidentally that night.
I wrapped the phone in a piece of cloth and left it in the hot sun for 1hour. Yeah hot weather here in Juba (South Sudan) today.
I was so glad!