"Base Terrain" and "Tree & Detail Objects" settings do not sync on another terrain using the same terrain data in the same scene or additive scene

Steps to Repro:
1. Open attached or create a new project
2. Hierarchy window > right click
3. 3D object > terrain
4. Duplicate terrain
5. Inspector go to terrain settings
6. Change base terrain or tree & Details setting

Actual Result:
1. Values are not synchronized for two different terrains using same terrain data
2. Wind settings and resolution settings are getting synchronized

Occurring with:
2018.3.01, 2018.2.0b4, 2018.1.0f2, 2017.4.3f1, 2017.2.2f1, 2017.1.3p3

Environment:
Windows and Mac