I had the same issue with my Galaxy S9, but this was a bigger problem then I thought. I had phone just under two years. I was away for a couple of days with family. Was at beach a couple days phone was in beach bag whole time was there. The last nigtht got moisture warning. Phone was never in water or water spilled on it. Tried all techniques to dry charging port. Phone would never charge. Brought to repair shop and they said it was not charging port but LCD and they said water damage because of red dot. How could that be? phone was never in water or spilled or anything but maybe next to damp clothes at most. Has anyone seen this issue before?