Unknown album not displayed in Lumin

[cassette]

Hello,
I'm a new user trying out Minimserver, which is a big improvement over the Synology/DS Audio I was using before. My setup is an iTunes library on a Synology nas - Minimserver, BubbleUpnp, with Lumin on iPad as controlpoint streaming to Chromecast Audio. This works very well but I noticed that tracks with an empty album tag don't show up in the Lumin song, album, artist, genre etc. view, while they are visible in the Lumin browser mode. Would there be a way to display these songs without having to fill in the empty album tags?
Thanks,
Joris