Hello! I had the same problem some time ago. I tried the typical solution of putting the cellphone in rice and wait but it did not work. The solution of using rubbing alcohol and clean it up with a Q-tip works, but sometimes, the cellphones does not reset the state of wet and it is hard to charge it again, even when is completely dry. I needed to turn off the phone and then connect it when it was on the process on been turned on, then the test is going to be run again. Also, if you want to turn off the notification of wet charging port, you should also delete the data of the USB Settings app, inside of the Apps menu (showing the system apps).
Those two solutions helped me to fix the problem. I hope that helps you as well. The A8 is a really good device and this issue is very common but also, very easy to fix.