pfSense

rectification for the BRIDGE, create an interface BRIDGE with the LAN and an openvpn links.

what version are you using?

site 1 : 2.1.2 with BRIDGE lan, openvpn link and LAGG of 2 openvpn (multi wan: 1 vpn per wan)
site 2 : 2.2RC last update with just BRIDGE lan, openvpn link

which side doesn't work?

both. specifically, one that reboot.
so that it works again, it is necessary after the reboot, resave the bridge configuration (or LAGG for the site 1) on the side that reboot.

at boot, i think at the time of initialization of the BRIDGE (or LAGG), the vpn is not yet initialized, and this creates a problem.

After the patche of bug https://redmine.pfsense.org/issues/4257
the BRIDGE is OK, but not the LAGG
On 2.2RC last update whith the patch https://redmine.pfsense.org/projects/pfsense/repository/revisions/145eb9907c638f5a1cf279b480a69bb3556c3b7e
an interface LAGG with 2 VPN mode TAP is always down after reboot, We must resave the LAGG configuration to make it up

And the interface LAGG is BRIGED with the LAN