Thanks again @benjamin !
Over the weekend we did more testing and isolated this Roon pausing cause to the Roku Ultra.
Looking at the Orbi router log at the date/time the music paused showed the IP address for the Roku Ultra to be the probable culprit. Roku had updated their OS (to 12.0) at about the same date that we had started to notice Roon pausing. Since this Roku update was pushed out and automated, we were unaware that it had happened.
Now with Roon running and connected like it had been originally, but with the power to the Roku Ultra unplugged, Roon works as it should and does not pause unexpectedly. YEA!
So the solution to this Roon pausing issue was to remove the Roku Ultra, with Roku OS version 12, from the network. Here are 2 links to more about what Roku OS 12.0 is all about:
@benjamin thanks again for your help with troubleshooting this issue!
Happy listening!
Carl