Roon remotes not connecting to ROCK core

I apologize if there are multiple entries for this case. I’m not sure my first entry was received since I did not get an email confirmtion.
How do I confirm that my ROCK cores are authorized? I have 2 ROCK cores running on Intel NUCs. One is new the other has been up for over a year. After I brought up teh new one neigther is allowing the iPad remotes to connect. I cannot manage these units. I see them on the web browser but not the Roon Remote app.

are you sure your remotes are indeed on the same subnet as the cores?

are both NUC cores using good DNS and gateway settings? Fixed or static IP? Wifi for wired?