OK, thanks for that link. That does explain some of it.
I have some weird ones, though. Fort example, when I edit the source, I see this message next to Hallmark Channel: "notAuthorized: Access to this program is not included in your Spectrum TV subscription. To learn more about adding this program, visit https://www.spectrum.net or call (855) 757-7328". I am subscribed to it, though. Also, if I rescan the one channel, it displays: "notAuthorized: ok"
I also see this message next to Discovery, TLC and a few others: "403 Forbidden: Access to the requested resource path has been forbidden: [Authorized Networks: None]."
Some of these channels have succeeded on previous attempts, but are now failing.