i have s10+ and i have the exact same issue,without dropping or even going near water, the issue/bug seems to be from firmware update maybe, as i have trued all methods including cleaning the port, drying it out, resetting the usb port data/cache setting etc... today oneUI update came and for the first time since last 2 weeks just now i charged the phone while keeping its on, without having the mositure/check usb port issue, lets see if the oneUI update fixed that issue, will keep you guys posted In shaa Allah