Hey @Joshua_Nelson,
We’ll take a look at your Core logs as this is highly unusual behavior. Roon ARC doesn’t function like a Roon Remote; the app shouldn’t have been able to influence playback on a Zone which was already playing in Roon.
Since I’m about to crystalize this into a Wiki in the #arc-testing:port-forwarding-solved section, I’ll follow up in a new thread with @Joshua_Nelson when we find a clue in logs.