Just done a little bit more digging. In the pveproxy access log I see a - 403 error when the IP having issues tries to connect. All the other connections are passing information correctly. I am not sure what this actual means though
87.xxx - root@pam [28/01/2021:11:22:52 +0000] "GET...
I have a bit of a strange problem. I can access the webgui from two different locations, but from a 3rd I am unable to connect and get
This site can’t be reached The connection was reset.
Checking the connection
Checking the proxy and the firewall
Running Windows Network Diagnostics...