As in title, I'm unable to insert custom music discs from Etched to the levitating jukebox, even though they work in the normal block jukebox.

I had a similar issue, except the jukebox simply ate the disk (I can't verify what mod it was from because I could never get the disk back). In addition, immediately after this I became unable to remove the collar from the pet, as it simply duplicated itself AND the jukebox. The monkey now has 4 jukeboxes slightly offset orbiting him and I cannot remove the enchantment.