This is an issue that has been reported on several sites. ITV doesn’t seem to work from the EPG, but the ITVX app does work. This, when using a VPN.
There is another thread discussing this and a possible solution using SmartDNS. You don’t say which VPN provider you use, but if you use NordVPN then a SmartDNS subscription comes with it. Other VPN providers may do the same. Here’s where the discussion starts.