Try have a look at the info here as it can fix some of these issues:
https://community.ee.co.uk/t5/Mobile-Broadband/Party-Chat-on-Xbox-Connecting-to-PSN-using-EE-4G-Rout...
Essentially try to access the Admin settings on the Router, find Profile Management under the Data Connection settings and create a new profile with all of the same details as the Default but change the IP Type to IPV4 only, then Set As Default and the router should restart.
If you're stuck on any of the steps come back to us and we'll see if we can coach you through it.
Instructions on accessing admin settings should be on the Keep Me card or a sticker on the router itself.
