Hi there,
We have seen sporadic issues with our ES440/450s whereby the web interface does not respond after a node reload but the node is passing traffic as you describe. Typically simply reloading the node again resolves the issue. If you can’t physically access the node and if you have SMS capability through your provider, you can try issuing a &&&reset command (by default, requires the last 4 digits of the SIM as the password so complete SMS string would be: PW xxxx &&&reset where xxxx is the last 4 digits of the SIM.)
Cheers,
Adam