On resizing a docked Progress Window, its icons for 'Success', 'Cancelled' and 'Failed' flicker continuously and/or disappear.
Refer to the attached video.

Steps to repro:
1. Create a New Project
2. Window > General > Progress > Dock it
3. Resize the docked window

Actual Result:
Icons for 'Success', 'Cancelled' and 'Failed' flicker continuously and/or disappear

Expected Result:
The window should resize without flickering or missing icons

Note:
Background Tasks/Progress window was introduced in 2020.1.0a18

Reproducible in:
2020.1.0a25, 2020.1.0a23

Working fine in:
2020.1.0a22,2020.1.0a18

Environment:
Occurring on Windows 10 & Mac 10.14, 10.15

License type: Pro