Error access T21P

[kychifre]

Hello I have the following error, the T21P phone with firmware 34.72.0.76 becomes very unstable, it does not respond to the buttons on the phone, when I try to access via web I get the following error.

You are not authorized to access the web interface.

Please contact your support team or try again three minutes later.


HTTP 401

I will return to factory settings and it worked two days, now it has happened again the same but works although I've reset to factory defaults.

Any ideas?

A greeting.