[dubwat]

Thanks for replying.  Will do tomorrow (for obvious reasons)

I've a Vero 4K+, kept as stock as possible.  It's latest osmc build/kodi 18.5/Nov '2019).  Never installed any extra skins.  I also have Kodi on a Win10 computer but just for messing around with skins etc (music files are copies).  It's currently 18.4 & same problem.  

One thought.  The album cover photos in your screenshot above look smaller than mine (oh err, missus).  My music started life on a Win10 computer and I embedded album photos as 700-1000px images in each individual music file.  My mistake (because... future proofing  ).  I didn't know any better at the time.