ifconfig bridge1
bridge1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
    description: vpn bridge
    ether 58:9c:fc:10:ff:81
    inet 172.16.20.2 netmask 0xfffffff8 broadcast 172.16.20.7
    id 00:00:00:00:00:00 priority 32768 hellotime 2 fwddelay 15
    maxage 20 holdcnt 6 proto rstp maxaddr 2000 timeout 1200
    root id 00:00:00:00:00:00 priority 32768 ifcost 0 port 0
    member: vnet0.9 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>.  -> used by the specific Jail
            ifmaxaddr 0 port 11 priority 128 path cost 2000
    member: vlan10 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
            ifmaxaddr 0 port 5 priority 128 path cost 55
    groups: bridge
    nd6 options=9<PERFORMNUD,IFDISABLED>
I guess that is the expected outcome.