Maybe I’m acting a little stupid.
My shield is between my ISP modem and my home network.
ISP (192.168.178.1) <=> WAN (192.168.178.2) Shield (192.168.177.1) LAN <=> Home network (192.168.177.0/24)
So far so good.
If I activate OpenVPN, I cannot connect.
My ISP modem has port forwarding (1194) to 192.168.178.2
And I have set up a static route (ipv4) from 192.168.177.0/24 to 192.168.178.0/24
Maybe someone has an idea or the same problem. Without Shield I already had OpenVPN running on a Raspberry and it worked very well.