CRS309-1G-8S+IN not responding

Hello,
I have just bought an CRS309-1G-8S+IN and rebooted to swos 2.10
I access it with the 1g interface. Connected 4 10g DACs.
While I was l browsing at “stats” page the web interface stopped responding.
I have tried rebooting it and resetting to defaults but without luck.
It seems the 10g dacs are switching correctly, it is just the web interface that does not work.
How can I solve the situation?
Thanks,
Mario

Should I assume it is broken?

I would guess that CRS309 received a management IP address from the DHCP server. By default, SwOS will try to query an IP address for the first 10 seconds, so see if your DHCP server has assigned some address for the switch (you can change the settings to static address as well, see the manual). You can also use a serial console to see the management IP address.