As I noted previously, Roon helpers are monitoring our system. This is what they reported after our most recent endpoint dropout.

What we saw in logs was a control-layer disconnection between the Meridian and your Roon Server on the local network. The endpoint (the Meridian) stopped sending expected data to the Roon Server, and the latter had to broadcast a device announcement and then re-establish a handshake with the Meridian to continue playback.

They have instructed me to initiate playback to our Meridian endpoint and the internal HDMI port in our Nucleus at the same time, and see if both are dropped during outages or just the M endpoint. (Evidently the HDMI port doesn't need anything connected to it.)
I'll report what we discover.

John

Main: 861v8, 818v3, 8000XE, 7200HCUSE, 7200.2, Roon Nucleus+, Shunyata Everest w/ Sigma XC and Alpha NR's, HD621, Oppo 103D, Panasonic P60ZT60 plasma. RJ45 switch on master SpeakerLink lines to select 861 or 818, Etherregen & ENO AG feeding the 818, M-Links.
Room #2: 5200.2s from M218.