New AU plugin not showing up in Logic Pro X

Hey, I recently downloaded the free version of Auburn Sounds' "Graillon 2". It says that it is available as 64 bit VST2, VST3, AAX, and Audio Unit plug-in for Windows and macOS. So the issue shouldn't be that. I installed it, quit and reopened Logic multiple times, still doesn't show up under Audio Units. I even went to the Plugin Manager under Preferences and hit Reset and Rescan Selection which is what I normally do when this occurs, and yet it still won't appear. I even went into my Library folder to check that the vst's had been placed in the folders correctly and they had been. So as far as I can tell, everything should be normal, and my plugin should be appearing. Does anyone know if I did something wrong, or if there's a detail I missed...?