Is it rooted?
IME Samsung will not allow rooted devices to upgrade their firmware, it says an update is available but will not allow you to do it. It could also be the reason why ITV will not work (although doubtful), Netflix has put systems in place to try and block rooted devices accessing it. There has been a real clamp down on rooted devices by some companies recently.
I would try downloading and testing some older versions of ITV from apkmirror before looking at upgrades, etc.
Last edited by rhoobarb2002; 11th May 2018 6:07pm.