P: Shortcut Shift Z (Loupe - Live) doesn't work on Mac

The shortcut Shift Z is assigned to Window > Secondary Display > Loupe - Live. On Mac, it works exactly once and then is ignored (though it works correctly on Windows).  Tested on LR 11.5 / Mac OS 12.5.1 and Windows 10.

1. Restart LR.

2. Do Window > Secondary Display > Loupe - Normal.

3. Do Windows > Secondary Display > Loupe - Live and observe the mode changes to Live in the upper-right corner.   

4. Do Windows > Secondary Display > Loupe - Normal and observe the mode change to Normal.

5. Type Shift Z and observe the mode change to Live.

6. Type Shift Z again. On Windows, it toggles the mode between Normal and Live. On Mac it does nothing until you restart LR, though the menu command Windows > Secondary Display > Loupe - Live continues to work as expected.

This was discovered while working with Per Berntsen, who observed changing and flaky behavior trying to change shortcuts in TranslatedStrings involving Shift Z:

https://community.adobe.com/t5/lightroom-classic-discussions/translatedstrings-trouble/m-p/13151502 

As with Loupe - Normal and Loupe - Locked, the shortcut Shift Z for Loupe - Live is hardcoded into the app. There are entries for it in TranslatedStrings:

"$$$/MultiMonitor/LiveLoupeShortcut/Mac=Shift+Z"
"$$$/MultiMonitor/LiveLoupeShortcut/Win=Shift+Z"

but changes to it are ignored.