Help with Google Workspace Auth

Because there are no Google Slides activities built into UiPath that I’m aware of, I’m creating custom c# scripts that will perform the actions I need using the Slides API. I’m authenticating with the same service account key JSON file that I use for the GSuite Application Scope, and it works to the extent that I can create a new presentation and perform certain actions, but it seems I cannot access or upload any files to/from a Shared Drive even though the service account email has been added as a Content Manager to the drive.

What further complicates this is that when using the GSuite Application Scope and activities from the Google Workspace package, I am able to get files, create files, update files, etc. in this Shared Drive using the SAME service account key. This makes me think there’s something wrong with my c# script that is preventing access that way. But I’ve spent hours trying to determine what could be wrong and am coming up short.

So I’m wondering, is there a way to get more insight into how authentication is being performed inside the GSuite Application Scope? Can the underlying activity code be shared for informational purposes? Or is there a way I can create a custom activity that leverages the authentication inside of the GSuite App Scope?

Screenshot references below:

Members/permissions in the Shared Drive

GSuite app scope properties

C# script being run as Invoke Code in UiPath

Output when run - notice it DOES see the RPA shared drive and not another shared drive that it does not belong to. However, files in the RPA shared drive are still inaccessible: