New SB8200 - improper provisioning

I just purchased and installed a new Arris SB8200 for use at my home to replace an aging SB6120.  I followed the installation instructions and I called cox customer service to register the new modem via it's SN and MAC address.  The modem is connected and I'm able to connect to the internet.   But here's the problem...   My download speeds are horrendously slow now.  Immediately before I disconnected the SB6120, I ran a speed test and I was getting in excess of my current plan speeds.  ~60Mbps down and about 7-8Mbps up.   Now, the same test yields around 10Mbps or less down and, at times, really high upload speeds around 20-30 Mbps. 

I have checked all of the signal levels reported by the modem webpage and they all appear nominal.  It also appears that all 32 download channels have been bonded and 4 upload channels are bonded (see bottom).  

Here's a current speed test report from the cox website.  as you can see horrendously slow on the download side which is less than 10% of what I should be receiving.  

So what gives?  I know that many other cox users including those in Phoenix and elsewhere in AZ have reported that this modem works as advertised when provisioned.   Has mine been provisioned improperly?   I know from other users of the modem that the firmware version being pushed out by COX and other providers is at least one or more revisions older than the modem's current firmware revision which is:

Why is my quality of service all of a sudden negatively impacted by upgrading my modem (which is something Cox want's you to do every few years) to the latest model which is officially supported by Cox?  As a long time cox customer going back 17 years, this is not meeting my expectation of performance and service currently.  :-(

I am not connecting to the modem wirelessly, but through a wired Ethernet connection.  I have tried connecting directly to my PC and through my router and the results are exactly the same.