Time to call the plumber and get those pipes unclogged. There must be something amiss on their end IMHO - my iOS devices show hundreds of proxy images for each artist in the Artist view on my iOS devices, but my Mini and rMBP only show a few dozen, and on my iPad and iPhone there's no matched set of artists with a proxy image - some show up on one device but not another.
It's being taken offline for a move I'm making, but it's working fine right now. Any keyboard presses take you out of the screensaver (Except for volume but I think thats always been the case), or click the exit button in the bottom right corner, but the mouse stays in the screensaver allowing interaction. So, I tried one more time - it was a slow night - and this time the hi-res artwork has stuck, even been downloaded to the main library on my Mini Server "talking" to my iTS Match account, which I checked about 20 minutes ago. Edit: Actually I did get it to play music, you double click on the album you want to hear. Last night as I was wrapping up my day I switched over to iTunes (I'd been listening to music in the background) and noted that pretty much all of the hi-res artwork I'd re-re-uploaded was gone again - but this time there was no low-res artwork in its place, just the blank place-holder but none of my other artwork had changed. I'm seriously thinking that Apple owns a company of or has an agreement with a nationwide network of therapists or pubs. I just launched my ATV and found that most of the new changes "stuck". That the low-res crap showed up on my Mini is what really bugs me. I uploaded new album art AGAIN, using my MMed Mac, and it propagated AGAIN on my iOS devices and my Mini Server's library. I even went so far as to (on my MMed Mac) sign out of the iTS, delete the iTunes library in the Music Folder, and sign back in to the iTS - it didn't work, sooooo. The album art that was borked had previously shown up in my main and MM libraries (iOS and Mac) until I deleted them in the past and uploaded new art. None of the music purchase on the iTS or imported from purchases elsewhere (Amazon, Xbox, and Google Play) appear not-borked. Albums that I ripped that are not in the iTS were not touched - across several genres. The sole common trait that I could find is that the borked album art was for albums I ripped AND are sold in the iTS. I have my Mini Server next to me and an iPad Pro, so I took some time to go through my Matched library and found a few dozen albums - all ripped that had been borked. Click to expand.I'm still grumpy about this, but less so than earlier.