Found here: https://developer.apple.com/forums/thread/90090
D&B make buckets of money off of paid services which are like credit counseling and business reputation rackets. If you want to borrow money as a business you’ll probably have to pay their tax along the way.
Their quasi government mandated monopoly is handing out the number you need. God forbid you try to get one from the former however. Also don’t try to update your registration through the paid side either. They’ll try to charge you even though they can’t get it done any faster than you can yourself through the correct link.
The key to getting one quickly is making sure your corporate registration is updated with your state. And the officer getting the Apple ID is listed with the state as an officer.
However, if you have had months of issues getting a DUNS number you likely are beyond wanting to move around a temporary roadblock, and on to trying to remove a more permanent roadblock first.
Getting a DUNS number for my LLC was free and not difficult, but it was confusing. There are a lot of wrong ways to try to go into the process - to the point where the DUNS sign up now has "Apple Developer" as one of the reasons you are asking for a number.