Images failing to load/display

Recently having trouble with images for all sorts of things, including creatures, spells & items, not showing.

Even when opened in edit mode, I just have the small preview text & placeholder. Weirdly, it’s not 100% of my content having this issue, and it seems also inconsistent which ones are affected between PC(Windows) & mobile, however, still having the same problem despite trying different devices.
Closed & re-opened F&F, refreshed & restarted. It’s been like this for a while with stable internet & Wifi. This is also occurring both in workshop and in campaign worlds; it’s not limited to just one.
I also tested creating a new item & generating an image, which seemed to work. I don’t know if the image will persist, however and would much prefer a fix rather than going through hundreds of blank images restoring them myself if possible.