To configure A190 in M300 environment its needed to change a setting from the config file and reboot, an later apply the modified configuration file

We recommend to use 450B13 firmware version

Step 1

Export configuration

Step 2 

Modify value of allow_call_groups to off as show below

Step 3

Reset Base to factory defaults

Step 4 

Import configuration exported and modified

Select File from Configuration tab, and later press on Load

Step 5

Configure as show in manuals

You should register A190 and M25 with differents account, after that , you can pair M25 to A190 to have one extension for both in the IPEI Tab -> Pair Option as shown, pressing over the IPEI number of M25 extension selecting as paired terminal Terminal Idx where x is the A190 Id

For any doubt please contact us in helpdes