OpenVPN - Via UDP no routing

[PotatoCarl]

Hi

I have since some time a problem with OpenVPN:
I have setup 4 legacy servers on two outside WAN lines.
- WAN is coming in via fixed IPs on FritzBoxes -> Forward Host (OpnSense).
- Two OpenVPN Servers (legacy), one UDP 1194, the other 1195, each bound to a different WAN
- Two OpenVPN Servers (legacy), Port 443 TCP, one to each WAN line

When I connect via UDP I get a connection. That means IMHO that the OpenVPN is setup correctly so far.
However, I cannot do any name resolution (time out), ping to any computer in the connected network etc.
Basically I get "VPN connected" and get "offline".

When I connect to the Port 443 VPN it works almost fine (see below), i.e. on any Linux PC everything works perfectly as expected. On Android, too.

I tried various firewall rules (I don't think I changed anything to stop working, as I use the VPN daily I should have noticed instantly) either using the OpenVPN nets directly, an Alias with all combined, or the OpenVPN_Network presetting. Nothing changes anything, on the UDP line it does not seem to get routed.

All OpenVPNs have set the DNS to the real IP of the OpenSENSE (which runs unbound), not any guessed IP from the OpenVPN network.

As I have the update to the new network ahead of me, I'd prefer to get the UDP running to translate "port by port" to the configuration and switch off "seamless" the system instead cutting off all remote VPN users all at once.

Any ideas, any one? Am I missing a "new" firewall rule that is mandatory here and might have been introduced even a couple of major versions ago that stopped working suddenly?

Firewall live view BTW does not show anything blocked, making it more confusing, unbound does not show a connection attempt.

Thanks for any ideas where to look.