Our freeview box occasionally has a hissy fit if you flick the channels too fast and does that thing of saying "New channels have been detected on the flow", and makes you wait a minute or two while it downloads a "list". You then have the option of clicking Yes or No to accept this "list" without knowing what is on it.
So it did this several times yesterday, and now I come to it to find BBC1 and BBC2 totally gone. They used to be channels 1 and 2, which now don't exist. They aren't re-assigned to any other numbers - I've checked.
Heeeelllp!!