How to regenerate thumbnails from “original” file not from the -scaled.jpg

I have a problem, in my wordpress installation some image sizes (on some devices) are messed up (half/partly written jpegs). i tried to regenerate thumbnails with plugins but that does not work out, because WP will regenerate from the -scaled.jpg and not from the original. But the -scaled.jpg is corrupted and so it creates corrupted thumbnails as well. Any ideas how to workaround this? thx

• This topic was modified 4 years, 7 months ago by freemee. Reason: changed link to article with broken images on mobile devices (retina))

The page I need help with: [log in to see the link]