I would also check the value of zimbraMailHost on the mailnode that zcb points to. This value should match the server name used at the time of 'BlackBerryServer(Manager)' mail profile configration.
In case if server name matches i may need some logs to troubleshoot further. Please try the following:
- stop BB controller and BB manager
- enable zcb logging (
ZCB and BES Logs - BlackBerry - Zimbra :: Wiki)
- start BB manager
- post snippet of zcb log file with "bbmgrw32.exe" component in the name containing keywords 'SyncGALRequest' and 'SyncGALResponse'