Currently I'm using Untangle NGFW and deployed in Hyper-V
the LAN interface is set to source and the WAN is set to destination and in the firewall the LAN is set to bridge. for the last 4 years the setup served me well
in OpnSense i have used the same settings in Hyper V and followed the instruction mentioned in here (https://docs.opnsense.org/manual/how-tos/transparent_bridge.html (https://docs.opnsense.org/manual/how-tos/transparent_bridge.html)) but i can't ping the upstream router there is no internet, i have all options in the virtual switch of hyper V (Source, destination and non).
the mac address for the LAN and WAN are correct between the Hyper-V and Opnsense
i have fixed the issue, you require to enable router advertisement guard in Hyper-V