Is port number 55000 the port number which is displayed in the Roon app under Settings → Roon Arc? If not, you should change the port forwarding to the port number which is mentioned in the Roon Arc setting tab in the Roon app.
It is not. I must have misunderstood the directions. I thought 55000 was universal for Roon ARC. Will report back.
Yes. That worked. I feel pretty dumb because I thought it was weird that the listening port didn’t match the forwarded port. I told myself it was some NAT on the LAN side.
This is from the manual. In my opinion this should be changed to something like Check the port number from Settings → Roon ARC in the Roon App. @support is that an idea?