Puid lookup including release and media, if the recording with the puid is track 1 on the medium then the offset paramter in the track-list element is missing.
look at recordingc0b7b368-ad18-481f-9184-2d92fa5799df and release 60ad15f3-a76d-42fe-b6d6-f2b01e13ce39 it says
when it should be
<track-list count="2" offset="0">
like releases where the first track isnt the first track on the media.
This wierdness has broken my application, and maybe others like Picard so suggest this is important.