Reproduction steps:
1. Open attached project "test.zip"
2. In Project window, select "Assets" folder
3. Scroll down

Expected result: Window scrolls past "Assets" folder
Actual result: Window remains locked with "Assets" folder at the top

Reproducible with: 2020.2.0a18, 2020.2.0a20
Not reproducible with: 2018.4.26f1, 2019.4.6f1, 2020.1.1f1, 2020.2.0a17

Notes:
1. Issue does not reproduce when selecting any nested folder within Assets
2. Issue reproduces on a popup Project window
3. If issue does not reproduce, try readjusting the Project Window layout to a height without a scrollbar, and then back to having a scrollbar. Additionally, focusing on other windows and then back to Unity seems to trigger the bug somehow.