Nell'ultima comuncazione dicono da AVM che non è un problema fw... mah
According to your description, the 2.4GHz Wi-Fi of your FRITZ!Box cannot be found anymore or just in an extremely short distance between client and FRITZ!Box. This is not a firmware issue but causes by inapropriate settings in the FRITZ!Box or a hardware fault.
Please test the following:
Make sure that the SSID of the FRITZ!Box is visible (and not "hidden").
The LED "Wi-Fi" is permanently lit
The problem persists after having loaded the factory settings.
If the problem persists, the hardware of the FRITZ!Box has to be considered as faulty.
We regret that your device is defective.
We will gladly test the device free of charge under our 5-year manufacturer's warranty here at AVM Berlin and exchange it if necessary.