Hi there!

Currently i'm facing a problem with OpenVPN on the TP-Link Archer C5400.

I connect to the OpenVPN server using the OpenVPN GUI tool, and this usually works fine for about 2-7 days. 

After this period the OpenVPN GUI tool shows the following errors:

Tue Mar 12 09:54:16 2019 WARNING: No server certificate verification method has been enabled.  See http://openvpn.net/howto.html#mitm for more info.
Tue Mar 12 09:54:16 2019 TCP/UDP: Preserving recently used remote address: [AF_INET]00.00.00.000:1194
Tue Mar 12 09:54:16 2019 UDP link local: (not bound)
Tue Mar 12 09:54:16 2019 UDP link remote: [AF_INET]00.00.00.000:1194
Tue Mar 12 09:55:16 2019 TLS Error: TLS key negotiation failed to occur within 60 seconds (check your network connectivity)
Tue Mar 12 09:55:16 2019 TLS Error: TLS handshake failed
Tue Mar 12 09:55:16 2019 SIGUSR1[soft,tls-error] received, process restarting

Then i need to stop and start the server and usually it works again.

Does anybody know why this error occurs?

I am using this method as my only external entry to the network, so this method has to be reliable.

I already have added a NTP server to synchronize the routers time with. 

Thank you!