Why are new contacts not added automatically from the handset to the computer contacts resp. from the computer contacts to the handset?

Open the Settings - Contacts tab in the Gigaset QuickSync and check the following settings:

 

The "Automatically add new PC contacts to handset" check box offers the option of automatically adding new contacts on the computer to the handset contacts. If it is checked, new contacts added to the computer database are automatically added to the handset. If it is not checked, they are not added.

 

The "Automatically add new handset contacts to PC" check box offers the option of automatically adding new contacts on the handset to the computer contacts. If it is checked, new contacts added to the handset directory are automatically added to the computer database. If it is not checked, they are not added.