Thumbnails on external storage are broken when at external storage root

[rubrik]

Version 13.0.0

Using "External Storage" with local filesystem directory (sharing: enabled, previews: enabled).

• Create new external storage pointing to local filesystem directory

• Ensure sharing is enabled, ensure previews are enabled.

• Copy image to external storage folder

• File view: thumbnail okay, can view large image. Gallery view: thumbnail okay, can view large image.

• Create share link to folder.

• Open link in new private browsing session.

• File view: thumbnail okay, cannot view large image "could not generate a preview of this file". Gallery view: nothing happens. Logging in other browser says "Exception: Could not locate node linked to ID: 22813"

• Create share link to image.

• Open link in new private browsing session.

• I can see it (!!!!)

Now I do the same without External Storage: it all works.
Now I do the same again (with External Storage) - but first I create a sub-directory: it all works.

This worked fine in NC12.

[rubrik]

I think my issue is a dupe of #7181

[MorrisJobke]

I think my issue is a dupe of #7181

Closing then as duplicate.