Struggling with the search options

I am currently trialling Roon, and I am struggling with the search options. I seem to be getting different results when searching in different ways. For example, if I click on the Albums tag in the side bar and set the filters to Johann Sebastian Bach and Vocal Music (as a subset of Classical) I get 10 results. If I click on the Compositions tab and Focus on Johann Sebastian Bach, Vocal Music doesn’t even come up as a category. I have had similar discrepancies with other searches, with far fewer Compositions returned in searches than I would expect. It is very frustrating - if I want to see all available Mendelssohn piano concertos, for example, I don’t want to have to look in every album. What am I doing wrong?

I am running Roon on an Apple iMac with my music library and Qobuz enabled, streaming to a Linn ADSM.