I haven’t tried any older versions yet, but should be able to over the weekend. I did find another post with what sounds like the same problem: Itunes Server on My Cloud Mirror Disappears
That poster had an earlier firmware version and two client machines running iTunes 12.3.3.17 and 12.3.2.35. No solution for that post.
I might try an iTunes 11.x version to see if there is any impact.
