PFSense OpenVPN TLS Handshake failed

[Clotilde]

I have a PFSense Router with a OpenVPN Server running. It was working perfectly fine. Today I tried to connect and got the following error in my OpenVPN Client:

Mon Nov 11 21:18:02 2019 TLS Error: TLS key negotiation failed to occur within 60 seconds (check your network connectivity)
Mon Nov 11 21:18:02 2019 TLS Error: TLS handshake failed PrepaidGiftBalance

I sniffed the tcppackets incoming on the PFSense OpenVPN Server. The PFSense does not seem to answer the packets coming from my client, the packets are all the same like this (captured at the interface of the PFSense where OpenVPN Connections arrive):

1 0.000000 78.43.*.* 192.168.1.156 OpenVPN 84 MessageType: P_CONTROL_HARD_RESET_CLIENT_V2

On the PFSense the OpenVPN Server is bound to the right interface. Everything else seems normal. My Client is Pingable from the OpenVPN Server. Ports on both sides are filtered|open for OpenVPN. Can someone help?