Download speed problem with 3rd party modem

History of my issue::

Worked perfectly for almost 4 years - consistent download 750–800 Mbps.

Around mid-August 2022 my download dropped by 300 Mbps. I watched it for several days and called Xfinity.

August 24, 2022 – tech came out to check all cabling outside and up to the modem. He then stated that it was the modem. The modem works fine, it just drops on speed and was not malfunctioning like on and off.

I went out bought a new Motorola MB8611 modem (sanctioned by Xfinity) and installed it. Download speed was the same. Called Xfinity and they said a tech needed to come out.

August 29, 2022 – tech came out to check all cabling outside and up to the modem. He then stated that it was the modem. Tech was baffled and said a Supervisor would call me.

No Supervisor called at all. I called back to Xfinity and was told that because the issue was not repaired it goes to a tier 3 so that when a tech come next time a Supervisor will be there as well.

September 5, 2022 – tech came out and before he started I asked if he was familiar with the past notes from the last 2 visits. He said NO. I told him that I was told that a Supervisor should be with him to tackle the trouble call. He said he would call his Supervisor for guidance. The tech said no Supervisor was coming because he was a 3rd party tech (with an Xfinity labeled truck). He was definitely confused. Finally, the contractor Supervisor got a hold of the Xfinity Supervisor. The Xfinity Supervisor said I will be calling the customer.

Again, No Supervisor called at all.

August 29, 2022 – tech came out. I asked him if he read the past notes. He said he did, but could not work on the ticket because my 3rd party modem did not have my Xfinity phone service-connected and it was a liability. I actually pleaded with him and then he checked the line inside the house only and said it looked fine. He stated that I should buy another brand of 3rd party modem. The download speed was still degraded. No fix by this tech.

I went out and bought 2 Arris SB8200 modems. I called Xfinity again and they said that another tech needed to come out. No other way.

September 12, 2022 – tech came out to check all cabling outside and up to the modem. He then stated that it was the modem. Tech could not fix the download problem.

I called Xfinity again. They said again that a tech had to come out for the repair.

September 16, 2022 – tech came out to check all cabling outside and up to the modem. He was baffled at the download speed. A supervisor did show. Why I have NO IDEA.

I called Xfinity again on September 19 trying to get an XFINITY modem provisioned (what a job over the phone). The reason I went to get the Xfinity modem is to prove that the speed is still the same as a third-party approved Xfinity modem. Can somebody in God's name tell me what this company is doing? They waste resources, but always want your money at the end of the month. I am now going on #7 for a tech visit on September 21, 2022.

What do think will happen this time? This is turning into a Circus for sure. I never had this issue before. I am pretty sure that a config change on their network/infrastructure side has caused my almost 4 week pain with these people. Xfinity said they saw a problem over the network on the downstream to my modem. I was told multiple times by the Xfinity tech person on the calls that they saw the errors. What the heck is going on HERE?

Does anybody think somebody at Xfinity will read this or maybe figure this issue out?

I asked one of the techs, which 3rd party modem does Xfinity recommend I purchase to remedy this problem. No answer – fell upon deaf ears.