Try this.  It works for me.   https://us.community.samsung.com/t5/Galaxy-S-Phones/Moisture-detected-in-charging-port/m-p/1651922#M38948 ... View more

Try the procedure in my comment linked below.  It always solves it for me.   https://us.community.samsung.com/t5/Galaxy-S-Phones/Moisture-detected-in-charging-port/m-p/1651922#M38948 ... View more

Check my reply, linked below.  I have the same problem and this procedure fixes it every time.   https://us.community.samsung.com/t5/Galaxy-S-Phones/Moisture-detected-in-charging-port/m-p/1651922#M38948 ... View more

I have this problem every time my phone is updated.  It is 100% a software bug from Samsung as my phone is never near water or high humidity when it happens.  The steps below are the ONLY way I've found to solve it, but it works every time.  If you've gone through this thread and are still having problems, TRY THIS!   1. Make sure charger is unplugged from phone, but still plugged into the wall. 2. Press and hold Bixby+Power+Vol Down to enter maintenence boot mode.  3. Release all three when the screen goes black. 4. When menu appears, select boot normally by pressing and HOLDING the Bixby button.  Phone will boot.  Continue holding Bixby. 5. When you see the Samsung logo (Samsung only, not Samsung Galaxy with Android), plug in the charger.  Continue holding Bixby button. 6. After boot is complete, it may still show the moisture detected warning.  Click OK. 7. Release Bixby button The warning should go away and your phone should be good until the next time Samsung decides to send an update. ... View more