Really disappointed that after only opening a new Samsung S20 for less than 3 months this moisture alert appeared on my phone. Definitely have not had phone near water etc. Contacted Samsung and despite a factory reset, after everything else failed, still didn't resolve this issue. I'm relieved I wasn't overseas when this happened. Being reliant on a wireless charger is totally unacceptable. Always owned Samsung phones but this issue has really put me off.
I've seen a few threads similar to yours @gordiegem with it being a mystery sometimes why the pop up message shows.
Perhaps perform a forum search to find these.
Usually this self resolves after a few minutes.
It's also not always to direct contact with liquid.
It can be temperature changes that causes droplets inside the phone.
A Samsung Experience Store or Samsung Service Centre can run a diagnostic.
🌈 Stay Safe & Stay Alert. 🌈
Daily Driver > Samsung Galaxy s²² Ultra 256Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help.