Record button goes invisible, Mode icons are overlapped and unable to downgrade timeline package on editing track offset position of the animation clip while playing the editor

Steps to repro:
1. Open attached project
2. Play editor > Timeline> Cube Animation > Inspector > Move Tool
3. Move animation in the scene view.
4. Stop playing editor > Play again > Timeline.

Actual Result:
1. Record Button goes invisible.
2. Mode buttons are overlapped.
3. Unable to update the Previous version of Timeline package.

Expected Result:
1. The record button is visible
2. Mode icons are properly visible
3. Able to downgrade timeline package

Reproducible in:
2020.1.0a3, 2019.3.0b2, 2019.3.0a12

Working Fine in:
2020.1.0a1, 2019.3.0a11.

Environment:
Windows & Mac 10.14.

Note:
Timeline window appears blank in 2019.3.0a12