Thank you for the info. It looks like they are using a poor method for VPN detection.
I don't use a VPN but do have multi-provider, multi-homed internet connections. This is configured for load balancing and automatic failover. Also of note is that one provider uses DHCP for dynamic address assignment.
Correcting the problem required "authorizing" both networks ... :
- Force both my workstation and the Channels DVR hosts to route with provider A
- Sign on to YouTube TV and NBC Live from my workstation
- Add the YTTV source to Channels DVR
- Let the DVR run with that configuration for about 10 hours include the recording of a few shows
- Sign off of YouTube TV and NBC Live from my workstation
- Update network for workstation and DVR hosts to route with provider B
- Sign on to YouTube TV and NBC Live from my workstation
- Force a rescan of YTTV channels
- Let the DVR run with the new configuration for a few hours including recording of a few shows
- Reconfigure the network back to load balanced with auto failover
I'm sure I will run into this issue again, but for now it seems to be working well.
This is a bit of an edge case and is an issue with the providers not the Channels DVR service.
Though it could be easier to solve if the "Add Source" process and/or rescanning would allow more interactivity for individual channel authorizations, similar to the Hulu processing. Maybe you could add this to the schedule? 
Thank you for the help and for doing a great job with the Channels DVR product!