My problem was due to a LOW MTU over a VPN connection.
netsh interface ipv4 show inter
Idx Met MTU State Name
--- --- ----- ----------- -------------------
1 4275 4294967295 connected Loopback Pseudo-Interface 1
10 4250 **1300** connected Wireless Network Connection
31 25 1400 connected Remote Access to XYZ Network
Fix:
netsh interface ipv4 set interface "Wireless Network Connection" mtu=1400
It may be an issue over a non-VPN connection also...