I'm suddenly missing a thousand pictures from my Samsung gallery Slash my files. There are still a few pictures left in them, so0 this makes absolutely no sense. How did a thousand of my pictures disappear?
Did you did any other backup option to recover? Google Photos, Microsoft OneDrive, Samsung Cloud?
Go to MyFiles app to see if the pictures or folder are on trash folder
What phone model do you have specifically?
If you suspect a software issue with the Cloud you could report it through the Samsung Members app FYI