Photos removed from album when unttaged in browser view

[mfritzler]

I'm using xnview MP 1.9.1 64-bit Windows on Windows 10, about a 5 year old Asus laptop.

1. Create an album, say "Fishing Trip 2025"
2. From browser view select click on a few thumbnails. Insure they are NOT tagged with Ctrl-T
3. Drag selected photos to the new album
4. Click on album view and browser view to confirm that the photos are in the album, and that other photos are not in the album but are in browser view.
5. From the browser view, find one or two of the photos that are in the album, but click on them to select them in browser view
6. Observe that they are NOT tagged with Ctrl-T
7. Press Ctrl-T. Observe that the photos are tagged in browser view
8. Press Ctrl-T again. Observe that the photos are now NOT tagged in browser view
9. Click on the Album name, and observe that the photos no longer appear there. But photos I did not tag and untag are still there.
THIS SEEMS TO BE A BUG.
10. In browser view re-tag the photos.
11. Observe that this does not cause the photos to be visible in the album. The only way I have found to get them back in the album is to re-add them.

This is a bug because a perfectly reasonable workflow goes like this:
1. Tag say 14 out 45 photos in some folder. Say a folder from a fishing tip The good ones.
2. Assign a category.
3. Choose 5 out of the 14
4. Assign the 5 to an Album. So I'm using Album as a highlight of a category. I might also use an album to collect highlights from multiple folders, say, the largest fish caught out of 5 different fishing trips in 5 different folders.
5. Sometime later decide to process anniversary photos
6. In broswer view, use shift-T to select tagged photos. These will be fishing photos left over from an earlier session.
7. Press Ctrl-T to unselect the photos, thus allowing me to use Ctrl-T to select now only anniversary photos. BUT THIS removes the fishing photos from the fishing album

Let me know if I have misunderstood the intent and operation of the albums. I read in the form post from I think 2013 that albums were task-oriented whereas categories were content-oriented. I didn't understand the remark. If an album is a set of symlinks to real folders, then tagging and untagging them should not affect the album. But if albums are virtual folders created at usage by executing a SQL query, then if the SQL query includes the tag field, we might see the behavior I am reporting as a bug.

Clearly, I can get what I want by using more categories or sub-categories. But, as the behavior with albums is unexpected, it is a bug and causes me to redo the work of selecting the highlights.
Please advise.

[xnview]

Thanks to your detailed description I can reproduce the problem.

[xnview]

This problem is supposed to be fixed in XnView MP 1.9.2. Please check and confirm the bug fix here.