When I look at the Network adapters page, the VPN is setup as a WAN Miniport, and the Hyper-V adapters are setup as virtual ethernet adapters: So, that's most likely about how Windows' networking works and it's the one that's causing problem. It turned out that when the VPN is up, the https connections from the VM also ceased. I made it use the Default Hyper-V switch to make it more distinctive (WSL uses it's own Hyper-V switch). Then, I thought that might be the Hyper-V and it's networking that's causing trouble.
Today, (coincidentally) I've tested to install an Ubuntu Server VM using the Hyper-V. To stop automatic generation of this file, add the following entry to /etc/wsl.conf: # This file was automatically generated by WSL. To be sure that it's not an network adapter issue, I've tested it by using both Wireless and Ethernet connections, which also connects to different ISPs.I've also tested from firefox (in WSL) and it also waited for "Performing a TSL handshake to ", couldn't finish connection and gave "The connection has timed out" error after a while.I've also tried with -no-hsts and -no-check-certificate options, but result is the same.The date command in WSL shows correct date-time.To be sure that it's not a firewall issue, I've included all network connections, including the VPN connection to the Private group.The 5th step should also have been succeeded. What's wrong / what should be happening instead: (control) In Powershell, type wget -TimeoutSec 30, which still succeeds.In WSL 2, type: wget -timeout=30, which fails with message "Unable to establish SSL connection".In WSL 2, type: wget -timeout=30, which still succeeds.
Connect through a VPN on Windows using the built-in VPN client.In WSL 2, type: wget -timeout=30, which also succeeds.