So I encountered this issue yesterday too. I went to the store where I bought the phone and where I pay insurance. They didnt know why it happened but in another post, I had read that wireless charging worked. They tried this and it did work.
I bought a wireless charger for $32 and was able to use and charge my phone. 24 hours later my wired port is working again.
Just bought a note 9, and every time the phone completely runs out of juice I get that, the only solution was to wirelessly charge above 10, then magically the USB would work., Now I see I'm not alone
As of today, I too have this problem.
My phone died while I was out with my family. At no point in time did it get wet at all. In fact it wasn’t humid outside eith. Just a perfect January day in FL.
I stopped at a convenience store to purchase a wire to charge my S9 in the car. Never before have I seen the yield, water drop, or the not charging symbol come up on my phone.
I guess I will have to wait until I get home to the wireless charger to see if the issue resolves itself, as it did for others.