This is s exactly what is happening for me. If the phone (s8) is on it fast charges no problem ( eg no moisture problem ) . If I turn the phone off then the moisture alert is shown and it doesnt charge. This is obviously a software bug in the charging software/firmware. No combination of chargers , reboots , clearing usb memory, etc. has helped.
Samsung needs to fix this issue .
I had this same bumfuzzleness. My Galaxy 8 phone did not get wet AT ALL and was not splashed but it did go dead completely. I plugged it back in and got nothing but this water droplet icon and electrical plug error icon. Very frustrating when this is my only phone for work. I tried the hairdryer with no luck. The solution that worked was hold down the volume button and power button at the same time and plug in the cable. It came back up and is charging now. Thanks to Firestarryl for posting that solution.
I also had this problem which started yesterday. Holding down the volume and the power worked for me also. spending over an hour on Verizon chat did not help at all. My phone has never been wet or in the bathroom with the shower running. Samsung this is your problem. Please fix it.
This one worked for me.
Phone was down to 1% battery when I got the warning and moisture error, though phone has been near nothing damp. Though I'd be safe and turn it off while charging, so it would charge quicker.
Was at work so could charge off anything except laptop USB port, tried 3 different charging cables. Then I found this post, held volume down and power button and plugged in the charge cable, phone booted up and started charging.
Clearly there is a defect in the moisture detection system in the phones - how do we address that with Samsung?
I've also had this problem off and on (conveniently, right after a year mark) and now it appears to be permanent--notification as soon as I unplug, and no other "solution" has worked. Phone has never touched water. I'm honestly suprised there's no class action suit or anything like that given that there's been total ignorance of this being a permanent, known issue with no fix or replacement offered. Certainly the last Samsung I'll ever buy.
Thank you for reaching out to us. Can you confirm if there has been any physical or liquid damage to the charging port of the device? Are you using the standard charging cables that came with the device and do those cables allow you to charge other devices?