Waveform Zoom Reset Keyboard Shortcut not working

Rekordbox 5.4.2
Macbook Air (Pre 2018)
OS 10.14.1
UK physical Keyboard
Default keyboard mapping (Performance 1)

I can't seem to get the waveform zoom reset shortcut to work. The default should be Shift + = but nothing happens when I enter that combination. The zoom in and zoom out shortcuts are working fine. I've tried changing the keyboard settings to US layout too but that didn't work (it gives the same key symbol for that key when layout is changed anyway)