"On Demand Remap" expand icon in "Materials" property under Import Settings is not getting clicked. refer attached video.

Steps to repro:
1. Create a new project
2. Import any Model file
3. Model file > Inspector > Import Settings > Materials
4. Click > On Demand Remap expand icon

Actual Result:
"On Demand Remap" expand icon is not getting clicked.

Expected Result:
"On Demand Remap" expand icon should be clicked and opened.

Reproducible in:
2020.1.0a6, 2019.3.0b5, 2019.3.0a7.

Working fine in:
2019.3.0a6, 2019.2.0f1.

Environment:
Window 10, macOS 10.14

Workaround:
Clicking on "On Demand Remap" label, Properties get visible