Weird Automatic Recommendation: is there a bug here?

I was recently recommended https://www.librarything.com/work/1047879 (a language primer for travellers to German-speaking countries) based on having the the following books in my collection, all fantasy novels by in English:
https://www.librarything.com/work/7056
https://www.librarything.com/work/472
https://www.librarything.com/work/47438
https://www.librarything.com/work/546
https://www.librarything.com/work/5266230

This seems bizarre, and its farther noticeable that the recommended book is 999,331st by popularity, with only 17 Members having it in their collections. (The books supposedly leading to it being recommended are far more popular.)

This might be an artefact - those 17 people might all coincidentally be fans of Mercedes Lackey, who is author or editor of all the works listed as reasons for this recommendation. (But - she's a very prolific author, and I have a lot of her works, so why only this 5? And why was this recommendation newly added on June 17 - 2 days ago, when I don't recall adding a Mercedes Lackey book to my collecton in weeks or months? Perhaps it's newly published? I haven't been able to locate a publication date.)

At any rate, I wouldn't be overly surprised by a recommendation for a book in German, or about German. I read German, and own both primers and some books in the language, though I'm not sure whether any of them have made it into my LibraryThing collection yet. But the reasons given for recommending this German primer to me make no sense at all, so I'm reporting this as a possible bug.

I can't comment on the other 16, but I have all those books in my library. I have not added any of them recently, though. My copy is from 2012.

I just looked at the others. One other is another Lackey fan, but has also not added one recently.

You can see the recommendations for that book here:
https://www.librarything.com/work/1047879

I agree this isn't the best set of recommendations. 16 copies is the lower (lowest) we generate, and it means some will be off.

Closing as not-a-bug, but this is one I'll be on the look out for, as I redo recommendations.

I am one of the 16 people who own that book. I also own several of the books in the recommendations (as well as a lot of Mercedes Lackey). But I have entered almost 10,000 books. Most of them have nothing in common with a book I bought for the use of visitors. Even the Japanese phrase book was from a one time duty travel my husband had in Japan a long time ago, and not related to my buying the German book.

I have marked down a few books I recognize.