I think I figured out what had happened. I think I had selected these additional channels from another guide listing (for a neighboring area) and had them, at least temporarily, included in the guide data. From there Jellyfin left the channel in the list of channels but without any guide data as it ...

When I scan for channels, I'm not seeing some channels that the HDHomeRun Flex is apparently finding in my area (enough so that Jellyfin has those channels coming through). In one case I want the channels that are being found (low power station from nearby area that I'm glad to be receiving). In ...