I am having the exact same problem and have been working with Jos. What we have found so far is that if we remove the two entries from the GPO that enable the SSO (there by breaking SSO) the OneDriveMapper script prompts for a password and maps the drives successfully. If we put the keys back in SSO now works but the OneDriveMapper script no longer maps the drives and complains about the required sharepoint entries being in the Trusted Zones files (which they are).
Let me know if you have any luck with it.
