How to reproduce:
1. Open up any project
2. Open Project Manager
3. Click on the + icon dropdown and select "Add package from git URL..." and insert a git package link e.g. "https://github.com/Unity-Technologies/Graphics.git?path=com.unity.postprocessing"
4. Click "Add"
Expected result: Loading icon and information on selected package appears whilst it's installed
Actual result: No indication that the package is being installed and Package Manager buttons "Install" and "Remove" for other packages and directories are greyed out whilst installing
Reproducible with: 2019.4.40f1
Not reproducible with: 2020.3.36f1, 2021.3.4f1, 2022.1.5f1, 2022.2.0a16
Reproduced on: Windows 11, macOS Monterey 12.3.1
Note: On macOS, even after the installation is complete of said git package, "Install", "Remove" and "Update" buttons are not functional