We have the exact same issue running 23.1 with an Watchguard M370 appliance.Lan port appears up but the connectivity is lost and it is not visible from the lat network even with arp -a.The problem happens infrequently every 7-14 days and is very difficult to track down. VPN and WAN interface work and the firewall management is acccessible when this happens (Through VPN). Zenarmor is activated, but it is not really doing much besides reporting: Routed Mode (L3 Mode, Reporting + Blocking) with native netmap driver.Will try with the emulated driver if that will fix the issue. The logs have nothing noteworthy from the time of the issue happening.Just installed the latest 23.1.6 patches but not feeling optimistic since this has happened multiple times already.Any ideas on tracking down the issue?
I had a similar issue some days ago. The bare metal LAN interface (intel) of my VoIP network lost the carrier and dropped its IPv4 address. A reboot solved the issue. But I don't know if this issue is related to yours.