Dual-WAN Setup, System's default gateway

[FraLem]

Hi all,
On a simple setup  with dual WAN & failover configuration it seems as we are missing a point.
Failover is working as expected for the LAN devices.
Opnsense  is resolving correctly through any of the DNS servers assigned to each gateway.
However, default gateway is not changing as first WAN goes down resulting in it not being able to reach a remote VPN Server.
Any tip would be appreciated.
Thanks

[FraLem]

Trying to troubleshoot, as both gateways are up active default route is set correctly based on the priority of the
gateway. However as active gateway goes down,  GUI shows the second gateway as active but routing  table is not modified.
Anyone knows which process is taking care of updating  the routing table as an interface Status goes to down?