jail lost network overnight (NAT)

[AJinNJ]

Setup a jail yesterday on TrueNAS-12.0-U8.1. Mostly default settings. Enabled NAT for networking.

All was good. Added some software to test. Networking was fine for LAN and WAN/internet access. Left it running overnight.

At some point the jail basically lost all network access. Can't ping my gateway or anything else. Restart did not fix the issue.

How do I get networking back and stable? Happy to send additional details. Any links to troubleshooting?

Code:

# ifconfig
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
        options=680003<RXCSUM,TXCSUM,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6>
        inet6 ::1 prefixlen 128
        inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1
        inet 127.0.0.1 netmask 0xff000000
        groups: lo
        nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
pflog0: flags=0<> metric 0 mtu 33160
        groups: pflog
epair0b: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
    options=8<VLAN_MTU>
    ether 02:1e:67:c6:39:c0
    hwaddr 02:2b:43:2f:ca:0b
    inet 172.16.0.2 netmask 0xfffffffc broadcast 172.16.0.3
    inet6 fe80::1e:67ff:fec6:39c0%epair0b prefixlen 64 scopeid 0x3
    groups: epair
    media: Ethernet 10Gbase-T (10Gbase-T <full-duplex>)
    status: active
    nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>

Pinging 172.16.0.1 says "Host is down".

Thank you in advance.