You should see me or my wife sometimes scrolling down this nine miles long single column list on the Roku to find a particular channel. It's in there, it just could be anywhere in there...
They didn't happen to post any new videos lately so they aren't on the main subscriptions page of latest videos, you have to go to the menu on the left to the list of all subscribed channels and just arrow down forever, back up, down again... Why in the ever loving world isn't that list at least alphabetical?
edit: has the added benefit that there are different feeds for All/Videos/Shorts/Live/Specific Playlists, so this is another way to avoid shorts