Search results are going to match to the words “Jethro Tull” so you’ll get some of their albums, as well as albums on which they are featured (like compilations), as well as albums like “A Tribute To Jethro Tull”, which may not actually feature any performances from the band themselves.
If you want a comprehensive overview of Jethro Tull, you’ll want to visit their artist page, where the music will all have a connection to the band themselves, as opposed to text matches to “Jethro” or “Tull” or “Jethro Tull”.
If everything works as expected, the band’s detail page should be “Top Result” when you land on the search results page.
Yup, this is a bug – an equivalence bug to be exact. @joel and I will take a look.