Hi salvo,
I appreciate you taking the time to report this issue. I will escalate your concerns and see if we can replicate the issue.
I have had more than one printer failure where the printer freezes up during a Restart/Reset after a configuration change. In each case it required a hard power cycle to recover (ie, the control panel was unresponsive). My first experience was during a firmware upgrade. My second, and latest, experience was after disabling SNMP.
This printer seems to be unstable with regards to Resets and Restarts, especially after a configuration change.