No default route !!

Hi, suddendly, one of our FGT (7.2.11) cannot reach the internet. Both wan are up and gateway reachable. the default route is set to the sd-wan. One 2nd firewall on another site with the same rules (pushed from a FMG) is fine .
all internal traffic is fine including to/from our IPsec vpn remote sites.
SD-WAN SLA are all up including the ones testing external dns. But an execute ping 1.1.1.1(or any exeternal IP) from the FGT give a Network unreachable. default route is set to the sd-wan

Any ideas ?