Accessibility Keyboard Shortcut Navigation on Mac OS Using VoiceOver

I'm doing some testing on a Storyline 360 course on a Mac using Safari and VoiceOver. 

On Windows machines and testing with NVDA, it is Ctrl + Alt + . for Next slide and Ctrl + Alt + , for Previous.  Those keyboard shortcuts DO work on the Mac (Ctrl + Option/Alt +. and Ctrl + Option/Alt +,) BUT they don't work if I have VoiceOver turned on.

Is there an equivalent command/keyboard shortcut for navigating slides forward and backward while VoiceOver is turned on? 

UPDATE: I opened a support case for this issue and I was told Articulate Support was able to confirm that the keyboard shortcuts I mentioned in this post DO NOT work on a Mac when VoiceOver is turned on.  It has been logged as a possible software bug.