Assume that you have installed an instance of SQL Server 2017. When you try to configure Automatic Tuning settings on ModelDB, you may notice that the ModelDB may not enable you to configure the settings. Therefore, Automatic Tuning settings won't be available on any newly created databases until you explicitly enable the settings.
This issue is fixed in the following cumulative update for SQL Server:
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Learn about the terminologythat Microsoft uses to describe software updates.