Thank you,
the adapter is 1,5 A but I’ll try with another more powerful.
I’ll also try to connect it to my laptop with a LAN cable and get the log to analyze.
I cannot say it reboots: the router shuts down the wi-fi. I tried waiting and sometimes, after two or three minutes, it has the wi-fi back but seems very slow in responding and keeps shutting down the wi-fi.
Led are not so helpful (only the red one blinking for some seconds, then steady for some seconds and then blinkink again. The 2 green steady until I proceed resetting manually)