Could not connect to external Wireguard server after update do 27.1

[Staddler]

Hi,
I used to use an external Wireguard connection to reach my companies network from my windows 11 host at home.
This does not work any longer after I updated OPNsense to 24.1.

The Wireguard protocol says:
Handshake to peer 1 (....) dit not complete after 5 seconds, retrying...

As far as I know, the Wireguard client uses UPD to communicate with the server.

I created a firewall rule in OPNsense to allow "any to any" with IP4 and TCP+UDP (just for testing).
The internal Windows firewall is deactivated.
Other Tools like Syncthing work fine. Syncthing also uses UDP on an specific port.

The OPNsense log-files does not contain any lines with the port I used for this Wireguard connection.

Does Anybody have an idea what's the problem could be?

[Staddler]

It's getting even stranger.
When I use Wifi, everything works.
Using an normal LAN connection does not work.

What could this cause?

[doktornotor]

Well, the current version is 24.7.x. I'd start there.

[Staddler]

Yes, Sorry. I User 24.7.