Categories Problem -- Categories create ghost "file" but don't apply to original file

[Sun Yat-Sen]

This is hard to explain. But say I have a file titled "sunrise.jpg," and I assign it a category "bright".

Now I use the category tab to look only at pictures categorized as "bright." What I end up seeing is a placeholder "blank" jpg icon titled "sunrise.jpg." When I select that placeholder blank icon, it shows it as having the category "bright" but I am unable to preview it, to view it, or even to "open containing folder." It's as though the category ended up applying to a ghost file that doesn't actually exist.

Meanwhile if I go to the actual sunrise.jpg file by browsing through folders in xnview, the file is there and viewable--but has no category!

Xnview is doing this with some of my categorized files, but not all.

Any idea what could be happening or what I could be doing wrong?

[xnview]

Everytime that you assign a category you have this problem? Could post a screenshot of Settings>Metadata?

[Sun Yat-Sen]

https://ibb.co/nwv22dz

(Hoping that url works)

[xnview]

So you use catalog only, no embedded data.
Everytime that you assign a category you have this problem?

[Sun Yat-Sen]

It happens for many, but not all, the files I assign categories to.

[xnview]

could you describe exactly what you do to try to reproduce?