Second WAN interface unusable since upgrade to 23.1

[scat70]

Hi!

ibg1 is for the second WAN gateway (172.16.1.1), igb2 for the first  WAN gateway (172.16.0.1). Routing looks fine:

root@opnsense:~ # netstat -rn | grep 172.16
default            172.16.0.1         UGS        igb2
8.8.4.4            172.16.1.1         UGHS       igb1
8.8.8.8            172.16.0.1         UGHS       igb2
172.16.0.0/24      172.16.0.1         UGS        igb2
172.16.0.22        link#3             UHS         lo0
172.16.1.0/24      172.16.1.1         UGS        igb1
172.16.1.21        link#2             UHS         lo0
192.168.3.0/24     172.16.0.1         UGS        igb2
192.168.5.0/24     172.16.0.1         UGS        igb2
192.168.178.0/24   172.16.0.1         UGS        igb2

igb1 is up and received a lease by DHCP. I can also see igmp.mcast messages send by the gateway on igb1. However, even so the network is local and everything seems to be fine, pinging the second gateway 172.16.1.1 fails and no traffic is seen on igb1 with tcpdump:

root@opnsense:~ # ping 172.16.1.1
PING 172.16.1.1 (172.16.1.1): 56 data bytes
ping: sendto: Invalid argument

I checked various post regading this topic, but none of it matches. This issue did not occur before 23.1

BR, Marc