I’ve got 11 bluesound zones in my house – 8 via 2 NAD CI580s (4 zones each) and 3 additional bluesound node 2s. I can confirm that rooms get out of sync all the time as others are experiencing. I hope the next firmware update that gets BluOS to the latest version of RAAT fixes it. I have found a work around though. If you group bluesound zones together in the BluOS app and then play the grouped zone in roon, things stay in sync. Though some of you might find that useful.