Streaming Picture Quality (Awful) Compared to Other Online Streaming Services.

So I just signed up for XFinity streaming today--switching from HULU Live.  I am streaming both apps (Hulu and Xfinity) from an Amazon Firestick 4K HD Max.  I still have my HULU Live subscription and the picture quality of Hulu Live is considerably better than XFinity for both live shows and onDemand.  Watching the exact same show, the difference between HULU and XFinity is night-and-day.  The XFinity picture is pixelated/grainy and looks like I am watching a 480 upscale.  The TVGO channels are slightly better than the live channels on XFinity but still look awful compared HULU Live.  Any motion or camera panning is nearly impossible to watch.  I do not see anywhere in the setting to adjust the picture quality or tell the resolution of the XFinity feed.  Additionally, I do not see any information concerning the compression or the bit-rate of the Xfinity feed.  I have over a gigabit down on my internet connection, so I know it is not a bandwidth issue.  Further, I stream 4k video on Amazon, Netflix, and Disney Plus on the same connection with no issues.  A 1080p feed from XFinity should simply not look this bad.

I have changed the setting son the Firestick to lock the resolution vs. auto; I have tried enabling/disabling HDR; I have ensured the system is up-to-date.  Again, other apps (Prime, Netflix, HULU) display good pictures from the Firestick--it just seems to be the XFinity App that has poor picture quality.

Also, when watching live TV from the XFinity website via streaming to my PC, the picture quality is also really bad--Again, much worse than any streaming service.  This is with picture quality set to "High" on a supposed HD feed.

Does anyone have any suggestion(s) on how to evaluate the resolution of the incoming feed or how to increase the picture quality--or am I missing something?  I expected the same picture quality I receive from other streaming services (at 1080p).  If this service is just a 480 stream "upscaled" to 1080p to place an HD label, I will have to strongly consider cancelling the service.

Thanks in advance for any help/suggestions.