Intermittent connection issues with Xfinity

Now the Advanced Tech team is suggesting me to file a complaint on Netgear suspecting it could be a Netgear Modem problem. The fact is that I have tried 3 modems(including Xfinity owned modem) and the result is the same. Also, how is it possible that Modem behaves badly only from 11-5 during the day and works fine the rest of the time?

Same here, Chicago area. I have 200 Mbps plan, speed became very irregular, like, 2 weeks ago, mostly stays in the area of 110Mbps; after modem reset or gateway reboot goes up to notmal 230 and then back to 50-100 after couple hours. Had about 6-7 calls to support, with no result, one time the guy tried to convince me that 110 Mbps is totally normal for my plan (I have only one wired device connected!), another guy today insisted he does not see any issues with my equipment.

My main gues is that with the begining of schools Comcast's channels are catastrophically overloaded and are unable to cope with the traffic; comcast authorities hiding this and are trying to manipulate with channels limitation below paid plan rates.

BTW, I also suspect Comcast hiding a serious problem with their DNS servers, when trying to open any new site it oftens takes forever and I also see 'site unavailable' error quite often. I switched to Google public DNS and it definitely improved the situation. Now it is just slow connection, placeholders instead of pictures, but no 'site unavailable' anymore. ip6 for google DNS are 2001:4860:4860::8888 and 2001:4860:4860::8844, ip4 - 8.8.8.8 and 8.8.8.4

Another strange thing I don't quite understand - if use ATT speed test it _always_ shows the full speed matching your plan, but xfinity speed test usually shows way lower numbers. Also, when I am watching network traffic in task manager window when running xfinity speed test, it usually rises smoothly until it reaches 118 Mbps (with my 200 Mbps plan) and then it is obviously restricted at that level, not even trying to go further. My point is - these are not local wiring or modem problems. These are traffic restrictions applied by Comcast to save their overloaded resources, and this explain why support guys can't and won't do anything here. Probably Comcast's approach here is  'squeaking wheel gets the greeze', that is, most users won't notice if they receive 20-30% less speed then they pay for; if you are persistent enough with complains, then they might raise the restrictions for you personally, but the majority of users will not make the waves and thus Comcast will save a lot of greenbucks.

We are experiencing the same issues.  It's like the back end of the process is hiccuping.  We were told that a major update for the system went out in late spring and that older modems were having issues.  They sent a tech to our house who installed a new modem, and that help for a few days and then the issues started up again (bad gateways, failure to load, timeout errors, etc.)  We are not heavy users.  We don't stream much, etc.  No one seems to know what happens, no one takes ownership, and when the communication path gets broken, you have to start all over again.  

I think they are not able to handle the load increase due to so many people Working from Home and with all school going kids streaming video classes.

I think Xfinity is throttling speeds/connections to compensate Load or simply their system cannot handle.

I have a Technician appointment tomorrow, lets see how it goes this time.

Whenever I call Tech Support, I get the reply that "Don't worry sir, this time we will solve it permanently, Thanks for being a loyal customer of Xfinity".

The only reason I am loyal is that there is no other option.

Update: I had a tech visit a few days back and he went on my apartment roof to check the connections.

He saw that my connection was connected via a 3-way Splitter with 2 other houses to the main node.

He moved my connection from the 3-way splitter directly to the main node and it helped! I haven't seen any connection drops yet, been 4 days. But this is not a long-term solution as Xfinity needs to do something to be able to handle all the Increased Load.

When I enter my modem admin console I also see a tonns of MoCA devices connected to my network, neither of them is mine;

When I try to disable MoCA network it gets re-enabled immediately after I saved the setting; talked to the support person for an hour over the phone, they managed to get it disabled but it re-activated after few hours.

Set all unauthorised devices to 'PAUSED' and ordered MoCA filter from Amazon.

Update:

received a MoCA filter from Amazon and installed it where the cable enters my apartment.

Since then for 2 days - no MoCA clients connected to my network, connections speed _GREATLY IMPROVED_, no more sudden disconnections etc. Also, my modem now always shows MoCA Disabled. Was this a remedy?If so, xfinity support demonstrated total lack of qualification, I asked them about those MoCA connections and they failed to diagnose it.

5 month old dead thread now being closed.

Same issues here. Tech came out the other day. Replaced the modem and moved it to a different room in the house. That didn't fix it.