Really sorry that it’s taking us so long to get to the bottom of this.
We think it as a problem with either:
- your ISP
- your router’s settings
- the network settings on your PC for the specific connection to your own network (the phone test ruled out a general PC problem)
Things we’ve though of which could help narrow this down:
- Change from connecting via wired Ethernet to WiFi. We believe this will create a separate network config on your PC. If that works, we rule out your ISP as being part of the problem, but it could still be your router’s config of wifi vs wired connections.
- Borrow a router and try that in place of your own. If this works, then we know it’s something to do with the configuration on your own router.