TheOwlGang Is OneDrive running on your computer? Even if you never use it, OneDrive could be syncing your data, and occasionally removing the files and keeping them only in cloud storage.
Separately, where is the game installed? Please open the EA App, click Sims 4 > Manage > View properties, and list the file path you see there.
To answer your question, yes, copying back the saves folder will restore them as long as you're moving them to the correct location AND the trigger for the saves being deleted doesn't happen right away again. But it would be best to solve the underlying issue.
I do not believe i have one drive up and running, but j can always check. And the sims 4 is just straight up installednon my documents folder
