Exact same thing happened to me, I ran a manual update.
After doing "update" again, one app/channel gets the update "Adding..." and it reappears at the bottom of the list. Doing another update and nothing happens, etc., until like 5 - 10 minutes later, it picks up another "Adding..." update, then THAT channel reappears again at the bottom of the channel list.
So, it may mean that just if you wait enough time, you can do a system update and the missing channels will all "Add" back.
So far, the channels that I have that "Added" back are:
- Science Channel GO
- Investigation Discovery GO
- Discovery GO
- Discovery Life GO
- Starz
It had picked up 12 updates in all, including NFL, Rifftrax, and I can't remember what else, so I guess I have to wait and hope that the other 7 channels are added back.
I could see that once the channel becomes hidden, it can't be accessed by searching for the channel and selecting "Go to channel".
I didn't realize until reading this thread that if you remove then re-add the channel, it still won't be able to work, I'm guessing until it's "Added" back in another System Update.
It messed up the order of my channels, I'm probably never going to be able to get it back just like I had it.
This is pretty major. I don't think I've ever seen something like this happen before.
