Transparent Firewall with High Availability

[RunTheEngine]

Hello,

i have two OpnSense (DEC 697) and configured like this https://docs.opnsense.org/manual/how-tos/transparent_bridge.html
LAN1: Management 172.16.16.0/24 + Default GW
LAN2: untagged VLAN 1
LAN3: untagged VLAN 1111
LAN4: PFYNC  10.0.0.x/30
BRIDGE: (LAN2+LAN3)
Alle 6 LANs conntected to Mainswitch Aruba R0X25A
Now we want to have a failover. We have add Pfsync (direct connection between the to nodes)

HA is not working:
With Spanning Tree -> no connection
Without Spanning Tree -> Broadcastflood
With Loop-protect -> better, but if a reboot one node, the interfaces are up, but the bridge not working and then a small broadcastflood.

Has anyone a working solution without a loop?

Best Regards
Momme