Today I found that some of my images are being saved with the .jpg extension but had no thumbnails. Using the “file” command I found out that the content is a riff container. It turned out that for somewhat reason some images have been re-downloaded containing the image in the webp format. Due to having nearly no support in Ubuntu/elementary OS for that and that they are being saved with the .jpg extension, it would be really great having them converted on the fly - perhaps via opt-in.
Fact is that I don’t understand why only some have been updated at some time. For example last week some of them were still jpegs and now they’re not. Most of them are untouched as they should be.