Welcome to this forum.
This is a customer to customer forum only,
This is where customers help each other get the most out of BT products & services.
Anything you post here does not go to BT. Although the forum is moderated by BT, not all posts are read.
To prove whether its a DNS issue, have you tried manually setting different DNS servers on your devices?
Thank you. The VPN tip has worked a treat. Didn't think of doing that.