Something about tags and green checkmarks that doesn't check

I use a tag "Planetbog" to indicate that a book is in the publisher series "Planetbog". I'm the only one using the tag and the 14 books in the publisher serie are the only one tagged with it.

As expected the 14 show up here:

https://www.librarything.com/catalog/bnielsen?&collection=-1&deepsearch=...

And here:

https://www.librarything.com/catalog.php?tag=Planetbog&view=bnielsen

And here:

https://www.librarything.com/catalog/?tag=Planetbog

but looking at the tag shows the 14 again, but only 12 of them has green checkmarks indicating that I have them in my library.

https://www.librarything.com/tag/Planetbog

The two weird ones are by Robert Crane and Sam Mervin.

Another uses the tag: planetbøgerne (that's just the Danish plural of planetbog)

https://www.librarything.com/tag/planetb%C3%B8gerne

This lists 9 books, but at least 3 of them are in my collection, but don't get the green checkmark.

I'm puzzled. I'd like to know what's going on and maybe also get to know how to fix it :-)

(Hmm, possibly some author confusion between Sam Mervin and Samuel Mervin and Mervin, Samuel Kimball, Jr. and Samuel Kimball Mervin, Jr? But I still don't understand what's the right thing to do.
Robert Crane is the pen name of Bernard Glemser, so that is also an indication about author confusion being at the heart of the weirdness)

>1 bnielsen: I didn't look at both titles but your edition of Enker klædt i hvidt has a typo in the author name, you have Sam Mervin instead of Sam Merwin.

e.g. https://www.findbogen.dk/enker-klaedt-i-hvidt_merwin-sam_2092873