We can't exactly pinpoint what the issue might be with your Mag, can be many things that's also why we would never recommend using a Mag device because of it's tight to a fixed mac address and memory issues, that and also Infomir the manufacture of these devices is blocking ITV services that running a specific firmware.
Firestick of Amazon is a good alternative that's more flexible and easy to set up and also when you want to use a VPN simply to install what we also highly recommend doing because of isp blocking ITV services as well, but when using a VPN you can get around this.
Well, the one thing that comes to mind to solve this Mag issue is to shorten your playlist with fewer countries so that your device has enough memory to load properly!