Hi
@LZettner
That parameter is unsupported and is known to cause erratic behavior, it's best to revert the change you made.
We do not recommend using it, and it is not going to achieve what you wanted anyway.
If you go to Contacts > Options you will see there is a choice to prepend the Ring Group name.
This is actually how external calls get forwarded to your phone:

The same thing applies to internal calls too, the information is included when we send the call
However, in the above example the caller 203
already exists in my device's phonebook so it matched and takes priority.
Basically, that is why you do not see the Ring Group name and the only way to change this is to either remove your extensions from the phonebook (can be done via 3CX) or modify the phone behavior (requires unsupported modifications).