Reset functionality doesn't work for Custom Blends in CinemachineBraine, refer attached video

Steps to repro:
1. Create a New Project
2. Package Manager > Cinemachine > Install
3. Hierarchy > right-click > Create Empty
4. Inspector > Add Component > CinemachineBraine
5. Inspector >CinemachineBraine > Create Asset > Click 2-3 times on "+" button > Reset

Actual Result:
Reset functionality doesn't work for Custom Blends in CinemachineBraine

Expected Result:
Default values should be assigned on reset

Reproducible in:
2020.2.0b3, 2020.1.5f1, with Package Version 2.6.2, 2.5.0
2019.1.0a1 with Package Version 2.3.3

Environment:
Windows 10 & macOS 10.14