Frequent Lost MDD Timeout

Yes. The downstream power is on the weak side and it may be intermittently fluctuating even lower out of spec. There is a condition that is called "cable tilt" (the rolling off of the downstream power at the higher frequencies) going on. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.

In an effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1000 MHz, bi-directional, and no gold colored garbage from Radio Shack, Home Depot, Target, etc. Splitters should be swapped with known to be good / new ones to test.

Also check the coax cable for any damage such as cuts, nicks, abrasions, kinks, sharp bends, etc.

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two-way splitter connected directly off of the drop from the street / pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to get the techs reinvolved until it gets fixed properly. 

Good luck with it !

A tech was here last June (2022) and replaced the 3-way splitter with a two way.  One output goes to me X1 box, the other to the modem.  There are no other splitters.  The tech checked the signal at the modem before he left.  All the cabling I can see is new and was supplied by Comcast.

Well if there is nothing more that can be done to improve the connection quality, then you'll need to get the techs reinvolved as was stated until the problem gets fixed properly. 

Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home. And if the problem is found to be on their side of the demarcation point, there will not be any charge.

Good luck !

Thank you.  I noticed that in other similar cases you said "I'm going to escalate your issue to the Comcast corporate employees that are available to these boards.  They can check the CMTS (Cable Modem Termination System) for any real time degradation and / or error reports, see your node / cable plant and modem health, and see whether or not everything is in the green zone. They can also see a history plot for the modem and poll for those upstream receive signal stats."

Would this not apply in my case?

The problem is obvious. Have you tried to see if any of those tips that I gave to you apply ? Nothing will be accomplished with an escalation (unless you want them to schedule a tech to come out). This can't be fixed remotely. It takes a *boots on the ground* / physical intervention.

A tech came to the house and found nothing wrong with the wiring.  He said he would escalate the issue.  After a couple of days with nothing improving, I called to ask for status.  They said he had left the ticket open but not escalated it.  They said they would escalate it but had to send another tech.  That tech came today and did more testing.  He also found nothing wrong with the wiring, but we noticed that during his testing, the SNR on all downstream channels dropped from the 40's tp the 30's.  He did more monitoring and found the SNR's to be fluctuating between the 30's and 40's.  He did a "service-effecting" escalation, and 2 line trucks came within 30 minutes, shut down the entire neighborhood got about an hour, thn told me they had found and fixed a number of problems effecting my service.

Since they left, the SNRs have remained in the 40's.  However, Downstream channel 8 continues to have hundreds od thousands of unxorrectable errors, and furthermore, I am not get Critical (level 3) events I never got before "No ranging response receiverd - T3 timeout".  Here are my current stats since a factory-reset I did when they

Now what???

Your post with the pics of the DOCSIS (CM) event log entries was marked as being "Private" by the forum software because it contains CM MAC and the CMTS MAC addresses. They are considered to be personal information. The posting of personally identifiable information is a violation of their forum guidelines. Please delete those two pics only.

What you can do instead is to copy and paste all of the text (instead of using an image) but you'll need to redact all of the CM MAC and CMTS MAC addresses. The forum bot will not allow your post to be seen publically.

Sorry, I would never have considered that personal information.  Here are redacted screenshots.

I just got off the phone with Arris tech support.  They said the Upstream power levels are the problem.  They are 32.00, and Arris says they must be in the range of +45 to +51, and that Xfinity can and should make this adjustment.  Does that sound right?