I'm following https://developers.google.com/drive/web/manage-sharing#launching_the_google_drive_sharing_dialog_in_your_app to add a "Sharing" dialog to my Drive app.
It works perfectly when the user is logged into gmail with a single Google account. If they log in to gmail with a second account, the ShareClient in my app no longer works. Instead, it says "Sharing is unavailable at this time."
To be clear, the change happens after interacting only with gmail, NOT with my app. I guess the problem happens because the share dialog doesn't know which user to default to.
Does anyone have a way to make this work? I would be happy to specify a google id, but ShareClient doesn't seem to have any settings exposed besides appId.