No access from LAN devices to OPNSense - internet traffic works

[JaroslawS]

Hi,
I have a KVM virtualization setup with a OPNSense VM connected to a bridge network on the WAN side and to a private network on the LAN side.
OPNSense has DHCP server enabled and the VMs do get IP addresses.
I can ping and access an internet site from the LAN VMs, but I cannot ping the OPNSense VM and access the web GUI.
I do not have any rules in the firewall that denies anything on LAN. I started logging the "Allow all  traffic on LAN" rule and I can see that the rule passed the icmp packet.
In a tcp dump I can see, that on OPNSense a ping request was received, but no reply has been sent.

I have set up a IPSec vpn which is working, but I do not get any traffic to the VMs, which seems right, as long as I do not even get a ping to work.
I have set up a OpenVPN connection to my local PC and from this I can ping the OPNSense vm and also access the web gui.

I'm stuck. Any advise is appriciated.

Thanks a lot.

JaroslawS