SharePoint Online - OneDrive - Read Only Sync Error

Hi, about a month ago several thousand of our document libraries based on content types started syncing to OneDrive in Read Only mode. When viewing the library in OneDrive, green padlock symbols appear alongside files and folders. The cause – although the site content types show columns as optional, mandatory columns from the parent content type have re-appeared behind the scenes – hidden from view.  These columns were made optional or removed on the site content type, but for some reason they've re-appeared.  The parent content types don't even have mandatory columns anymore. 
To fix:

1. Go to “Library Settings” then “Advanced Settings”
2. In the first option, choose “No" for “Allow management of content types” and click OK
3. On this next screen, in the Column section you will see the culprit columns are marked as Required.
4. Click the columns which are required, and change to option “Require that this column contains information” to No
5. After changing the columns back to optional, the folder in OneDrive should become available immediately.
6. Then go back to “Advanced Settings" and enable content types again
7. Finally, check that the files are again editable in OneDrive.

This fix provided by Microsoft support is not acceptable due to the number of libraries affected.  Is anyone else experiencing this issue?