How to reproduce:
1. Open the attached project '1182428test.zip'
2. Click on the 'Test' option on the Taskbar and notice the hotkeys that are mapped to different MenuItems

Expected results: All of the hotkey shortcuts show correct mapping
Actual results: Only F1-12 shows correct mapping

Reproducible in: 2018.4.8f1, 2019.2.5f1, 2019.3.0b3, 2020.1.0a4
Could not test with 2017.4 since apart from F1-12 the other shortcuts were not introduced yet
Not reproducible on Windows

Notes:
- All of the special hotkey shortcuts work both on Windows and Linux, but the Editor has to be focused on nothing because it coincides with existent built-in shortcuts.
- Link to the specific documentation page: https://docs.unity3d.com/ScriptReference/MenuItem.html
- PGUP does not show any hotkey shortcut at all