If the search in the ProCall Mobile app or in the ProCall Client for macOS does not return any search results from the MetaDirectory, this indicates an incorrect setting or lack of access of the clients to the network in which the UCServer or the MetaDirectory is located.
Make sure that the contact data source is correctly specified in the UCServer administration under Databases – MetaDirectory.
If user management is activated in the MetaDirectory, the UCServer must authenticate itself to the MetaDirectory. For this to happen, the "Use user ID" checkbox must be set in the UCServer and a user and its password must be specified.
The query at the MetaDirectory is performed by the UCServer "by proxy" with this user. The user must therefore be activated and also configured in the MetaDirectory. The ProCall Mobile/ProCall Mac users will be able to query the contact data that the specified user is allowed to see.