XFinity network changes breaks stuff.

Something is going on with Xfinity. After a year of getting bi-directional DOCSIS 3.1 on my SB8200, I no longer get upstream 3.1, just 3.0 (downstream remains on 3.1). A Google search indicates that the SB8200 is not supported in the Xfinity high speed advanced tier, but I'm telling you it worked great for a year with very fast upload speeds but no longer - now it is capped at about 24mbps (I'll live because I'm not a YouTube influencer).  Yes I have power cycled the modem. There are been no changes in the past year to my cabling or modem or plan. I'd guess the change was in the past month or two.

At the same time my mother, also an Xfinity customer completely lost internet and voice.  Three times we booked an appointment with a technician and then cancelled it, because we'd get a text message saying that "We fixed the issue impacting Xfinity Internet in your area. If you're back online, you can reply X to cancel your appt." and low and behold it would begin working fine. But the next day it would be down again - not able to lock onto upstream nor downstream channels. Finally we had a technician to her house - he spotted some old RG59 that had been there 30 years that he replaced with some RG6 and got it working because that's what Xfinity techs do - replace coax and splitters.  Nice guy, but almost no English and was watching tutorials on his phone.  But internet and voice had been working flawlessly for 3 years - not one hiccup since 2021. Very fishy.

So two anecdotes do not create data, but I'm convinced that Xfinity is changing things and breaking stuff - like my upstream DOCSIS 3.1 and my Mom's RG59 cable that was fine for the past 3 years. They will say that it is out-of-spec and I get that, but they are breaking stuff that worked fine before and impacting customers and I don't like that. I bet this is happening all over. So this is more of a vent than anything - if I complain about my upstream DOCSIS they will tell me that the 1 year old "recommended" DOCSIS 3.1 cable modem needs to be replaced with a new DOCSIS 3.1 cable modem to get faster upload speeds and that RG59 can't handle higher frequencies. Except both were fine before. If they made network changes that impact customers they should be communicated.

So color me not happy.  Posting this for others that might have noticed the same problems.