Cannot maintain a solid connnection

Continuing with more information:

The line techs have been busting their tail 100%.  They ran a new trunk line to the pedestal because their meter found a potential damaged spot about 80 feet down the line.  After replacing that, they also went to the amplifier, and actually replaced the amplifier and still no success here. Frustrated as I work from home and have to reboot modem every couple hours at minimum to get ANY kind of connectivity.

Im having the same issue with the same exact modem, got my service at the same exact time. Its really upsetting that Xfinity refuses to acknowledge its an issue with their firmware. They told me to just wait for it to fix itself essentially online while offering no compensation on my bill. Ive had line techs and in home techs out here and they are all clueless. Tier 2 tech on the phone also cant do anything. Im at a loss. They told me to replace my modem over the phone, but the techs that were here said not to and its an issue on their end but they don't know how to fix it.

We are getting closer....the line techs have been working feverishly on our entire neighborhood.  They have troubleshot SEVERAL noisy nodes in the area (including my own) and thru a couple weeks of the process of elimination, tonight we are trying a final test and things seem sto be working so far... we will see...

Well you aren't going to believe this....

Last night I tried 2 last ditch efforts. The first was to take the modem cable coming in and run it thru my UPs which hasa opto isolater that will run as 4gb speeds thinking that was take the noise off the line - however I found out later the opto isolater is only engaged under surge setting.  so i put it back to normal. ON A WHIM, I took my modem, laid it on it's side with the back pointing at the wirelss router (in this case it's a Netgear blackhawk R7000 but I will test with my archer 6000 later today)
Solid connectoin ALL night. No unicast errors. comcast had set up trending with YETI and noticed that the line was solid all night with NO alerts...

Might be on to something here... I find it hard to believe that something like this (the CM1200 from  netgear has NO shielding from wifi (it has no built in wifi).

More to come!!!

Here are my logs since yesterday afternoon. You can see the "TIME NOT ESTABLISHED" is when I last rebooted and the follow up notes from 18:53 (6:53PM which is actally an hour off of real time) so at 8PM last night I rebooted the modem after flopping it on its side.  You can see all the unicast ranging errors below - they were hapening about every 5-15 minutes. have not had ONE error since the reboot ad laying on its side.  Every time that happened, 3 channels would stop monitoring, until it got down to a single channel running.

I was very fortunate that the line tech (not the resi tech) gave my his phone number to contact him...we talkedthis morning and he's going to cut me a cable long enough to put the modem in another room so I can leave it standing up (also with 3 walls in between to block more wifi).

I am honestly astonished that this has solved hte problem so far...and astonished that a $220 modem doesn't have wifi rejection on it to stop it from happening in the first place...but, here we are!!!

I, as well as the line techs I'm talking to, would be interested if your works better this way too

Hello, I'm having the same issue and I'm using the same modem, although my wireless router is a Netgear RAX200. Called Xfinity a number of times and I get the same diagnosis. Curious to see if this works.

3 full days later,and my internet connection is rock solid....I am still finding it hard to believe that simply putting my modem on its side was the solution -

Going to test later this week by setting it up how it WAS and seeing if the errors come back