Images randomly disappearing without any changes made

We have a weird issue, and might have had for some time, where images are randomly disappearing. We haven’t made any changes to the site, but all of a sudden we realize that images are gone – specifically the ones with “-scaled.jpg”.

I have found the solution to be:

1) Go to the specific product that has a product image that exists in the media library, but does not exist on file server, and click “Edit Media”: https://i.imgur.com/q9kfAJs.png

2) Click “Rebuild thumnails” on the attachment: https://i.imgur.com/Z35g14P.jpg

3) The product image now exists again.

How come it gets deleted? It’s smaller sizes?