doing the guided setup fixed my problem...
I re-did the guided setup, chose the same service provider (TWC - Austin Digital) and after it re-loaded everything, including guide data, all of my channel listings showed guide data! In fact, it didn't even wipe "my channels" that I had previously selected to only see in the guide.
I'm not sure why a Tivo support staff wouldn't know to try this basic step but, oh well, I'm happy.
- - - - - - - -
Roamio Plus (3Tb)
Mini - Guest BD & Master BD
CC: Sci Atl PK802
TA: Cisco STA1520