Unfortunately we had a subtle issue in version 355 and 380 where the address book is not available after a roaming or an handover. This issue was fixed into the version 400B2, released in November 2017. In order to fix the problem and having the central address book prperly working you have to:
- Upgrade to the version 400B2
- logon on the web interface
- click on the Firmware Update link
- fill the Firmware update server address field with http://dect.snom.com
- For the fields Update Base Stations and all the handset please fill: - Required version: 400 - Required branch: 2
- Click Save / Start Update
- After the update you should apply a change on the address book (adding a new entry, or modify some of them) and wait for all the bases to download the new address book (by default 3CX is using a 30 minutes timeout).
If this doesn't solve your issue, please open us a support request providing the device settings and a syslog taken when the base downloads the central address book.