ipfw nat

I have an router on FreeBSD (13.3-RELEASE-p3) with nat via ipfw ifconfig age0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 options=c319b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4,WOL_MCAST,WOL_MAGIC,VLAN_HWTSO,LINKSTATE> ether...

Hi everyone! I need help with strange situation. There is a host (12.2) with jails, one of these jails is a vpn server (mpd5) with internal eth1=192.168.1.9 and another one is a mail server with internal eth1=192.168.1.4. The vpn jail is a vnet jail, and the mail jail is a simple jail...