this just happened to my S10e today in 4/20, just one day before my birthday haha, I just entered to see you guys' replies about this but I couldn't unload any app on the Play store in order to check if my photos were on my files app, also Samsung's My Files had everything vanished like it was a new phone, I couldn't capture any photos and my camera was freezing everytime I tried to take a pic. Also to mention that I was unloading Security Patch from April 1 2020, I odn't know if this had something to interfere with that. Another thing it was I couldn't hear any voice during phone calls and nobody could hear me either which was scaring me more already.
So I what I did is to securely restart my phone, with frighten that I couldn't see my photos again, I have like 2,000 now from like 7 years ago. My surprise is after the restart I had everything back in normal, my gallery, my camera, my apps everything. I hope this can help.
