How to reproduce:
1. Make sure that all applications are minimized
2. Open the project "case_1233766-AddressablesGroups"
3. Open the Addressables Groups window by selecting Window->Asset Management->Addressables->Groups in the Menu Bar
4. Expand the Default Local Group (Default) in the Addressables Groups window
5. Expand the Labels for any addressable in the expanded Default Local Group (Default) in the Addressables Groups window
6. Click the button "Manage Labels" in the Labels dropdown in the Addressables Groups window

Expected results: the Addressables Labels window is opened
Actual results: the Addressables Labels window blinks once and does not open

Reproducible with: 2020.1.0a22 (1.3.3, 1.7.5), 2020.1.0b6 (1.3.3, 1.7.5), 2020.2.0a1 (1.3.3, 1.7.5), 2020.2.0a5 (1.3.3, 1.7.5)
Not reproducible with: 2018.4.21f1 (1.3.3, 1.7.5), 2019.3.10f1 (1.3.3, 1.7.5), 2020.1.0a21 (1.3.3, 1.7.5), 2020.2.0a6 (1.3.3, 1.7.5), 2020.2.0a8 (1.3.3, 1.7.5)

Could not test with: 2017.4.39f1 because the Package Manager is not available, Addressables 1.2.4 because the Manage Labels button is not available

Notes:
1. It is not reproducible when the Addressables Labels window is opened by selecting Tools->Labels in the Menu Bar in the Addressables Groups window
2. After clicking the button "Manage Labels", another maximized application is brought to front (see the attached video)