Have you tried resetting the YouView box? I find the box sometimes needs resetting.
Try turning the box off and on at the back first and seeing if that makes a difference, if not then try a YouView Reset and choose option 4 ( Internet/USB Recovery, keep recordings) to keep recordings. I would also suggest that you try rebooting the router once you have reset the box.
If this works, you will need to reset your future recordings and personal settings. When you select a Sky channel you should then be asked if you wish to set up the channel again.
Let us know how you get on, and if it does not work then I'll leave it for an OCE to do further checks.