I have youview box dtr 2100,for about 4 months it's been freezing,i switch it off & it goes into wake up mode & works ok again for maybe a couple of weeks & freezes again.But foe about 3 weeks now i'm having a problem particularly when i watch something on prime.Whatever i'm watching will just stop & i find myself watching the last live tv station i had been tuned in to.I've now started watching all apps on my tv tuner to avoid this issue,no problem there.Could this be a problem with the youview box.
Go into the YouView settings and check that your YouView box has all updates.
If that doesn't work try resetting it (also in settings menu) but you may loose your recordings.
These boxes are very old now and even in good health they struggle to cope, they also have a history of Hard Disk Drive failure which I suspect is the real cause of your problems. If I'm correct then you will restart it or switch it on one day and it will fail to start up.