Thumbnail not displaying in simple item view for some items
Occasionally thumbnails don't show up in the simple item view for certain items when logged out (they do appear when logged in). An example item given today is https://hdl.handle.net/10919/116783. Note that in this case the thumbnail DOES display in the FULL metadata view, and in the collection browse list, but NOT in the simple view.
Previously we'd guessed that if the system has trouble loading a thumbnail when a page is first visited (by any user), a version of the page is cached without the thumbnail. When the cache expires, the thumbnail should be loaded again.
I found some related DSpace issues today.
- Thumbnail doesn't load immediately after filter-media runs. The thumbnail then shows when the cache expires. This was marked "WONT FIX" because it is expected behavior. I don't think this is our issue; doing a hard refresh in the user browser still doesn't show the thumbnail.
- Thumbnails don't always load when media viewer enabled. We have media viewer enabled, but I also don't believe that this is the issue on this specific item as we're no longer seeing the trailing dots. This issue should be fixed in DSpace 7.6.2 release
- Item thumbnails exist but don't load on initial route](https://github.com/DSpace/dspace-angular/issues/2660) Probably also not our exact issue because it's been marked as fixed long ago, and revisiting the page doesn't seem to fix it.