WS-12-250-DC Not Forwarding Packets

[valnet]

I installed a WS-12-DC on a solar power installation, having ordered the wrong device. It became quite unhappy at 57v and would shut down - to be expected, as its' voltage range specifies 37-53v.

So, I ordered the right part, WS-12-250-DC supporting 9v-72v per the label. Battery voltage on the solar system can get as high as 57.5v, so no problem there!

I backed up the configuration on the WS-12-DC and restored it to the WS-12-250-DC, and took it on site, connecting it up the same as the WS-12-DC; it booted up just fine and I was able to access the interface.

However, I immediately found that the unit would not forward packets even though it would ARP devices connected to the switch.. Thinking a VLAN mistake and possibly loop, I reduced the configuration until finally there was only one port active, and it couldn't possibly be in a loop. Rebooted the WS-12-250-DC, adjacent router, and backhaul to the site for good measure. Still no packets forwarded.

Thinking a possible problem restoring the WS-12-DC backup to WS-12-250-DC, I reset the WS-12-250-DC to defaults via the reset button waiting for the green loop, then red loop, and releasing the reset. It properly defaulted.

I applied a very basic configuration (loops impossible) and it still wouldn't forward any packets. Out of ideas, I swapped the WS-12-DC back in and it booted and worked flawlessly (until the voltage goes back up again!)

Brought WS-12-250-DC back to lab, defaulted it again, and made NO configuration changes - standard configuration, all ports untagged VLAN 1. Connected port 12 to my LAN and port 1 to a laptop. Laptop could not DHCP an address. Assigned static IP address to laptop within proper subnet, could not ping anything on the LAN. No packets forwarded even in a completely blank default configuration.

Suspect I have received a faulty unit from the factory. Any suggestions?

[valnet]

Looks like I had the same issue as viewtopic.php?f=17&t=6180

Clearly a firmware bug. Downgrading to 1.5.3 restored normal operation, upgrading back to 1.5.5 and packets still forward.