New Account Setup PHH Mortgage

While I can't disagree that if something's supposed to work then it should work, that CC-501 message indicates that the connection is Express Web Connect (EWC) and EWC is notoriously "fragile" and prone to glitches, particularly when compared to Direct Connect (DC).  The problem could be on either side: some error in the Quicken server's "script" that's trying to get the information from PHH Mortgage, or a change on PHH Mortgage's web site that hasn't been communicated to Quicken.  You might want to contact Quicken Support as suggested here:

so they can look to see if the problem's on their side of that equation.

But frankly I don't see any great advantage to having a connected mortgage loan, particularly when the information's coming to you via EWC.  First, you're not getting complete information from the servicer - nothing about interest or escrow - you're only getting an adjustment to the loan balance and nothing more.  Second, with a connected loan you have no access to the loan's register.  If bad information is pushed down to the Account you can't correct the error, and with EWC the changes of getting no information or bad information, (there's more than a few users that have posted that their loan is showing as "paid off" when that's not the case), goes up.