Clementine-->Strawberry migration

I applied https://wiki.strawberrymusicplayer.org/wiki/Import_collection_library_and_playlists_from_Clementine
and initially everything looked fine. The covers showed up as expected in the Cover Manager and the play lists seemed to have transferred as well. However when I played a playlist the cover was 'blank' even though the cover was shown correctly in the 'Cover Manager' This applies to all Playlists. The same applies to any newly created playlist. Any suggestions as to how to investigate and fix this would be welcome.