I also came across the
TLS key negotiation failed to occur within 60 seconds problem.
From the official suggestion, as Diamant post, there must be something wrong in the network connection. However, neither the firewall nor the NAT cause the problem.
In my case, I first checked the connection by
nc -uvz xxx.xxx.xxx.xxx 1194. The link is OK.
Besides, several other vpn clients within the same LAN work fine.
From somewhere I noticed that udp connection has some problems in response or port forward.
So I stop the running vpn clients from the largest ip to the hanging client, e.g, from “10.8.0.100” to “10.8.0.50”.
Then start the stopped vpn clients in reverse.
Bang! All the vpn clients work propoerly.
In conclusion, there is a chance leads to
TLS key negotiation failed to occur within 60 seconds problem that multiple vpn clients within a LAN starting in a wrong sequence.