Possibly BT Web protect, or BT Parental controls.
You could try using different DNS settings on your computer, as suggested in that thread.
I've tried manually setting the DNS to use Google's 8.8.8.8, 8.8.4.4 and disabled IPV6 too, but no change. I'll ask the account holder to log into the account and check the BT Web Protect or Parental controls.
Just quickly:
You are connecting directly to the BT HomeHub either via a cable or WiFi, and there is not a secondary router between you and the internet?
Yes, in fact I've two windows 11 PCs, one is connected directly to the WiFi from the Hub, and the Laptop I have connected directly by cable to the Hub. The Hub is connected directly to the BT Fibre. Neither will connect to the VPN when using the Hub, both connect to the VPN just fine when using my mobile hotspot.
Have you tried connecting your laptop directly to the ONT so missing out the BT router - there are instructions for doing that on other threads if you need them? This would establish whether it is something within the router causing the issue or elsewhere.
Is this a possibility?
Microsoft confesses April Windows update breaks some VPN connections
https://www.theregister.com/2024/05/01/microsoft_windows_vpn_problems/?td=rt-4a
I checked and that KB5036893 installed on 22/04/2024, however the problem has been present since I first connected to this broadband about 6 weeks before. I uninstalled the update to try that and no change.
Additionally, the VPN still works perfectly when I use my phone hotspot, so it certainly seems related to either the Hub itself or something within the BT service.
Ok yes, I have just setup connecting my laptop directly to the ONT, so bypassing the BT router altogether. I was able to connect and get online, however the VPN still would not connect, so this seems to indicate it's not the hub causing the issue.
You haven't said if you checked if web protect is enabled.
Sorry,
I checked. Both Web Protect and Parental Controls are off.