SD Card Unexpectedly unmounts itself while still clicked in.

When I have my SD card in, it will work fine for a while (just enough for me to transfer some files to it). My phone will then give me a warning that the SD was unexpectedly removed, and my files could be damaged. When I open the back, my card doesn't seemed to have moved and it seems securely clicked in. I'm not sure what to do from here. This started when I was hiking in a creek and slipped on a rock. My phone was wet and stopped working for a bit but now works fine except for this one thing.