You can modify your integration even if the Mac option is greyed out: it indicates it has been originally selected (Windows and Mac are mandatory, for the exact scenario you encounter!)
Nevertheless, modifying your integration will recopy the necessary files, including those for Mac, so if the issue is that you have missing files this should solve it.
If you encounter file access errors:
Failure to access certain directories may be a configuration problem where files are expected at a certain place, but have been moved, or a user access right access. There should never be a need to run anything as Administrator other than at installation time when prompted by the Wwise Launcher: running as administrator may assign the wrong rights to files and leave them unaccessible later on.
You can try starting from scratch by removing the Audiokinetic folder in /Applications/Audiokinetic, the WwiseLauncher and Wwise context in $HOME/Library/Applications Support/Wwise2019 and $HOME/Library/Application Support/WwiseLauncher and finally the settings in $HOME/Library/Application Support/Audiokinetic.
Make sure you are using the latest Launcher from audiokinetic.com. Running as a normal user in all circumstances and not moving files manually on the filesystem, there should be no file access issues.