Why doesn't my 1392 NO WIFI monitor ring when it receives a badge call?

Why doesn't my 1392 NO WIFI monitor ring when it receives a badge call?

In installations with only one monitor in the kit, we recommend checking the configuration of the monitor as it should be configured as MAIN. 

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Also, check the MUTE indicator if it is active, the LED   indicates that it has been muted. To activate it again, access the menu and increase the volume.