I ran into a problem on Ubuntu 22.04 where any ssh connection would hang inexplicably. It only happened on my home wifi network, not at work.
Resolved with this thread.
Change the network interface MTU to solve it. This is a bug for ubuntu 14.04. This worked for me:
sudo ip li set mtu 1200 dev wlan0
sudo ifconfig wlan0 mtu 1200
ssh fails to connect to VPN host - hangs at 'expecting SSH2_MSG_KEX_ECDH_REPLY'