MMM-Fritz-Box-Callmonitor // How to display internal calls & names?

[thk]

I am using the MMM-Fritz-Box-Callmonitor to display incoming calls on my mirror.
For number to name conversion I´m using a vcard file, which works fine for external numbers.

Actually I´m struggling to find a way to display & convert internal numbers into names.

I am using a SIP doorbell which is hooked up to the FritzBox as an internal phone.
When this one rings, there`s no popup on the mirror.

Does anyone know how to solve this?