Moisture warning in S or A phones using a C or B connector.
If you are adamant your phone has not come into contact with moisture it is probably dirt on the charging contacts. These ports are really small but this is what I used.
100 x 2mm cable tie
2mm strip of kitchen towel
Carefully glue the towel strip to both sides of the fine pointy end of the cable tie,
let it dry. Dip it in the isopropyl, carefully clean the contacts in the port without disturbing the centre prong or leaving any paper in it. Let it dry before plugging in to charger.
I can't be responsible for stupidity or no skills. but it certainly works for me.
Having spoken to Samsung UK I went through all the checklist with this fault and only the dreaded factory reset fixed the fault. Now I can plug my phone into my laptop and car usb ports and not get the error. Let's hope it doesn't repeat the fault!
I fixed mine by turning the phone off then taking a the end of a paperclip, with some tissue and jamming it in the port. Push it all around. Turn back on and was good to go. Hope this helps
I had this too, it's a short glitch
Changing chargers fixed it for me
I kept getting it & had to shut off , then restart my tab s3 everytime
Finally figured out my charger was worn out
I solve this issue on my Galaxy s7 Active by wooden stick for teeth cleaning. I cleaned contacts by it in 20 seconds after watching about 15 youtube videos and wasting about 1-2 hours ^^ My experience.
Just to let people know, majority of the time it is dirty charging port unless somone actually got the port wet. BUT there is also a possibility that the charging port has failed, yes, an actual hardware issue. I personally have tried everything from every site I have been to and every video I watched trying to get my Note 9 to charge by cable. The last thing I did a couple weeks back was the dreaded factory reset. I hated to do it but that was the last thing after weeks of trying everything I read and it did not help. My issue is 100% hardware and needs a new charging port which is where the moisture sensor is located. You must try EVERYTHING you can before giving up and having your phone tore apart to be fixed. I opted to use wireless chargers untill I find my next phone, which won't be a Samsung, after owning 7 Samsung phones. I was loyal, Samsung was not...