I had that from day one, actually started working properly after the update so the opposite of what you're having.Just wondering if anyone else on the newer firmware is having problems with All4? Had this months ago where you try to launch All4 via the shortcut, the logo appears for a second, then it just goes back to the TV/HDMI or whatever you were watching before. Can't get it to work via the EPG either.
The workaround was going to one of the 4 channels and using that to get to all4, it worked fine from there.
Edit, just noticed that doesn't work either... Sorry bud.