I'm seeing this on both my original "Top Missed recordings" playlist:

https://listenbrainz.org/playlist/a8cf5961-d420-4c3e-9d59-81661c6f165b/

and one that was manually regenerated:

https://listenbrainz.org/playlist/2621b984-50e6-4c52-a368-2cae26cf5e61/

 

The first 15ish tracks shown appear to be correct unique recommendations. After that, the same tracks are repeated 2 more times.

Testing the "top missed tracks" query on bono: https://bono.metabrainz.org/top-missed-tracks?user_name=kepstin produces an apparently correct list of recordings without any repeats.