Exported Baked AO Textures Blank

I’m trying to export the baked AO textures with Lightmapping.lightingSettings.extractAO. The lightmapping completes correctly and the AO textures are exported, but they are blank white. Using Unity 2020.3. Any ideas on how to export the AO data successfully? I’m ultimately interested in adding the baked occlusion data to the shadowmask.

Result:


Lightmap Settings:

Try the method outlined in this post: Ambient Occlusion without an Ambient Light