Reproduction steps:
1. Open a new or an existing project
2. Drag the Editor window to the monitor which is connected second to your computer
3. Select any GameObject in the Hierarchy window
4. Click on the Add Component button in the Inspector window

Expected result: The context menu opens where the Editor window is located
Actual result: The context menu opens on the monitor which is connected first to your computer

Reproducible with: 2020.2.0a20, 2020.2.2f1, 2021.1.0b3, 2021.2.0a2
Not reproducible with: 2018.4.31f1, 2019.4.18f1, 2020.2.0a19

Notes:
- Tested on Ubuntu 18.04
- The "Add_Component_Not_Maximized.png" picture attached below illustrates the problem