I have a Sony Android TV KD-49XG9005.  It has been working flawlessley for a couple of years now.  

Yesterday, I turned on the TV and I could not launch YouView or any of the related streaming apps e.g. iPlayer, ITV, Channel4.  TV broadcast works fine but pressing the guide button does not cause the guide to appear. 

Prime, Netflix, YouTube, YouTube kids all work fine.  Disney+ launches but when I press play on the film, I am returned to the Android TV home screen.  Very odd.  

I did a factory reset, set up the TV again from scratch.  All good.  YouView working with all apps.  Disney+ working.  Turned off TV, went to bed.  Woke up in the morning, turned on TV, now the same problem is back.  YouView is not working, related streaming apps not working.  

This is really confusing me as I can't see what has changed between turning TV off and on.  As I say, this problem only just started occurring in the last 48 hours after 2 years of no issues. Two factory resets and still the same issue so looking for help from the community.

Suspect an app update is breaking something in the OS or YouView?

Thanks

Ben