Same here. A couple of TVE channels that I've received for a long time now show: "not in subscription" when, in fact, those very same channels are in the basic cable package. For example, Discovery Life and REELZ are channels down in the SD group of channels (I think that's in or almost in the most basic Xfinity bundle). Via HD Home Run Prime access, I can watch both. Via TVE, I now get "not in subscription" on rescans.
A few notes to actually add something to this thread...
I also have the xfinity stream app on mobile devices and on very new TVs- a Samsung and a TCL. Historically, every channel I can get via Prime has pretty consistently been available in the stream app on mobile devices. On both the Samsung & TCL running xfinity stream as apps on those TVs, all but HD channels have been available for me.
Of late, I notice that in both apps for mobile and apps for the TVs, available channels (to which I subscribe) are coming & going depending on WHEN I open their app. A few days ago, I opened the app on the Samsung TV and there were NO channels available at all. In the mobile app version, there has been some times in the last few when only a small subset of channels are available. I suspect Comcast/Xfinity are doing something of bigger consequence than usual in terms of the system(s) that manages permissions. Since several of us are having very recent problems like mine, it appears it's not something tied to any one person's user name & password, or individual permissions. I suspect it's system-level changes/updates that are affecting us.
Last night, I attempted to access 2 (regional) Fox Sports TVE streams to which I've had long-term access, as I also get both of those cable channel versions in the Xfinity subscription. Both failed. Been here before with Comcast "reset password" adventures, so I opened the Fox Sports app and had a new kind of error message I had not seen before: something about not being able to tell that I'm in my local market (implying that it could not tell I'm at the same home where I've been with long-term previous access through their app). I believe it suggested I log out and log in to re-authenticate, so I did that and while their process was a "success!" going back to their live stream, home screen where I can usually pick an event to watch looped back to not knowing my geographic location again and showing me ZERO events in the background.
Perhaps some of you can check xfinitys dedicated mobile stream app and/or the xfinity stream app on applicable TVs if you have it. I bet you'll find that channels that should be there are not always there. And I bet the channel lineup in the app changes if you check several times each day.
And if you also have some dedicated channel apps like I do with that Fox Sports app, perhaps try using those to see if you can watch their stream that way. Especially if you know that some of those dedicated apps have worked before for channels with a TVE stream that is not working now, you may find- as I did- that whatever is going on seems to reach OUTSIDE of the Channels app.
Again, I suspect Xfinity is re-doing their permissioning system. Does it perhaps depend on Adobe Flash by any chance? Or maybe 2 hamsters running fast enough on a wheel? ;). Hopefully, whatever they are doing will get resolved soon.