SURF SOHO Locks up occasionally

Three times in as many months I have awakened to find my SURF SOHO MK3 (F/W 7.0.3 build 1260) off its rails. Each time, it’s WiFi AP remained up, as did the SSID beacon, but there was no DHCP service, so WiFi clients authenticated, but couldn’t connect (for Internet.) Similarly, there was no DHCP to a trial laptop with a hardwired connection to the SURF, nor any Admin Page access over that same wired connection with a manually configured IP in the same network segment (192.168.50.xxx). The Status LED was ON, the WiFi LED was flashing steadily.

The SURF’s WAN is in the DMZ of an AT&T 5031NV RG with its own WiFi AP disabled and no other wired client. The RG was observed to be working perfectly throughout the SOHO outage by substituting a wired connection directly to it in place of the SOHO.

A second SURF SOHO is wire-connected to the failing one LAN-LAN to extend two VLANs and thereby isolated SSIDs to guests and IoT devices at the other end of the house. This opens the possibility of transients from an electrical storm in the attic Cat5e interconnect overnight, though that second SURF was unaffected other than losing DHCP service and net connectivity from the first. It did not require a reboot. I can’t recall if previous outages were associated with storms or not.

There was no apparent way to recover admin access but to power down and reboot, after which the SURF came up normally.

After rebooting out of last night’s failure around 8:45 AM, the event log shows

|Aug 08 16:57:24|Admin: admin (192.168.50.100) login successful|
|Aug 08 16:47:06|Admin: admin (192.168.50.11) login successful|
|Aug 08 12:50:13|System: Time synchronization successful|
|Jan 01 00:01:20|WAN: WAN connected (104.13.80.218)|
|Jan 01 00:00:45|System: Started up (7.0.3 build 1260)|

Including the two admin logins I have running right now.

Should I expect the event log to contain some trace of what is occurring in the night? If not, are there logging options I should keep enabled in hope of determining what caused a lockup after a reboot out of it?

Dave