Done and done. We'll see if that solves the problem. Those downloads into my gallery only happened twice over a month's time. I may not have confirmation that the problem was solved for quite some time.
Thank you to everyone for your input.
Something you can also check is your sync settings in gallery.
If you open the gallery app and click on the three dots in the top right and select 'settings' turn off 'sync with samsung cloud'.
Then login to your samsung cloud account, either on the app or on the computer, and see what phones are connected to it. Delete any you do not recognize and then change your password.
Also in gallery click on the 'shared' album on the bottom right. See if you have any shared albums there. If you do, delete them, and try to see what you can do to unshare the albums.
This should also be a good place to start as well as safe mode.
good luck and please report back with any changes.