Reproduction steps:
1. Open user's attached project "Unity2020323f1.zip"
2. Open Shortcuts (Edit > Shortcuts)
3. Switch Category to "Main Menu"

Expected result: Shortcut commands are shown
Actual result: Shortcut commands are not shown

Reproducible with: 2019.4.33f1, 2020.3.23f1, 2021.2.5f1, 2022.1.0b1

Notes:
-Not reproducible on macOS
-Not reproducible when targeting standalone

Fault code example:
[InitializeOnLoad]
public static class StaticTest
{
static StaticTest()
{
if (ShortcutManager.instance!=null)
{
ShortcutManager.instance.shortcutBindingChanged += OnChanged; //this line causes the issue
}
}
}