While working on two instances of Unity of 2020.1.0a24 version, undocked windows of Unity instance running in the background pops up while operating current Unity instance. Refer the attached video

Steps to reproduce:
1) Create two Unity projects. Call them "first" and "second"
2) In first Unity instance, Window > Package Manager > Undock the window
3) In second instance > Press Play

Actual result: Undocked window of Package Manager of first Unit instance pops up while operating the second instance

Expected result: Windows of other instances should not pop up while operating current instance

Occurring on: 2020.1.0a24
Working fine on: 2020.1.0a23, 2019.3.2f1

Environment: Only on Mac