Displaying Disc Numbers in Multi-Disk Boxsets..?

[Ignatz]

Hi, don’t know if this a problem with the WiiM Home app, MinimServer or even mp3Tag, but disc numbers for box sets display weirdly… as you can see, sometimes there’s no disc numbers at all, sometimes there’s a disc title and sometimes I actually get disc numbers (whether they’re tagged in mp3Tag as ‘Disc Number:’ ‘1’ or ‘1/8’ makes no difference)… any idea what I should be looking at..? TIA