Thanks Mr. Jefferson! I ran into this problem uploading a Developer ID app to Apple for notarization. This happened on my new MacBook Pro, which I had imported my Xcode Developer Profile from my previous computer. It included the Developer ID Application and Developer ID Installer.
Apparently to use the Cloud-Managed Developer ID certificate, I needed to remove both the manual Developer ID Application and Developer ID Installer. After that, it worked spotlessly.
Thank you!