Motorola MB8611 modem frequently loses connection to Xfinity/reboots (yeah same here)

I seem to be able to relate to nearly everything people have posted in ‎Motorola MB8611 modem frequently loses connection to Xfinity/reboots | Xfinity Community Forum.

I purchased my MB8611 last April to go along with a speed upgrade after seeing that the equipment is Comcast/Xfinity certified. The line to my house was unprotected and poor and so crew came out and replaced it about a month later. (Great crew BTW.) Since then we've never achieved the target speeds, but it was an improvement. (Best I can do is 320Mbps down out of expected 1Gbps plan.) But so unreliable and unpredictable. We can go a couple of days without seeing an issue and then we'll have several drops in a couple hours. I cannot relate the drops to any usage patterns in our household.

I have chatted with tech support a number of times including two days ago. On multiple occasions a tech has been scheduled and then I get a message the next morning that someone has reviewed the issue and made a correction -- would I like to cancel my appointment. That "fix" usually seems to last around 24 hours or it is coincidence. The last cycle of this was two days ago. I did not cancel my appointment as it was another day out. Sure enough there were three drops the morning before appointment. (My router's system log has a very regular pattern when the drop happens; so, I now can so how often it happens even if I no one is actively using internet.)

A senior technician arrived and did basic line test for noise and claimed all is good. I mentioned that others have suggested that troubles arise from neighbors with older/faulty equipment. I do know that no one else has tried to update in last 5+ years and definitely will have the same unshielded lines to their homes. One said they think reliability has gone down in the last 2 years. Tech said others don't seem to have a problem so nothing he can do for me without seeing the issue. And so concluded that it must be my modem. I asked that he be sure to get that to me in email or such so I can get Motorola to replace it but I haven't seen that so far.

What I can say is that a prior tech did see the drop while present using their own equipment. They also found that cable coming to the wall panel by modem was bent and shielding had been damaged. Pretty sure this was after checking line noise and thinking things were fine. So, they fixed that and expected that to be the end of it. But I don't know how techs can expect customers to demonstrate the issue while they are there. In my opinion Comcast needs to be monitoring better to be able to detect problems. The tech I most recently spoke to didn't really know what data Comcast actually has access to.

To continue my situation, I engaged Motorola support and shared modem data. The rep doesn't understand how the Comcast tech can say things were good based on the connection report from the modem that I shared. The rep did confirm that once a sufficient number of errors are reached the modem will restart itself. That is designed behavior. (Unfortunately, the device doesn't keep a specific log that says it restarted itself to deal with that, but from the errors the rep is very confident.) So Motorola is going to replace the modem but doesn't expect it will make a difference. (I will incur a shipping cost to return the maybe defective or maybe perfectly fine device. :( )

I am hoping that someone can confirm from my connection report whether there is a line issue as Motorola says or it could be the device as Comcast speculates:

 

 

And here are the results 2.5 hours later:

Additional things that I wonder. Why is there a repeated pattern of contacting support and getting a tech service scheduled to then have someone else say they have fixed the issue? Since this repeats across customers isn't there something better that can be done? These modems are Xfinity Certified .. should that certification be rescinded? What is the deal?

There is a hint at the end of thread I posted that there is a known issue on Comcast side that just isn't fully being acknowledged. The Motorola rep kinda hinted at the same.