I had the same problem and tried the steps on this thread. It turns out that, if TV Plus is disabled from the homescreen, it completely disappears from the system unless the aerial type is set as "Terrestrial" (on the right hand side of the Channel List). Once you change it to Terrestrial, the TV Plus channels all reappear. You can then select a TV Plus channel and add the app back to your homescreen. Then you can change the aerial type back to your preferred setting (Freesat in my case). For me, however, this introduces the problem that the aerial setting changes back to Terrestrial every time I use TV Plus, so I lose all the Freesat channels, so TV Plus is currently unusable.
This is a UK model, in case it helps anyone.
