Significant Drop in download speed cbr750

I didn't do anything. 

Just like everyone I was very frustrated, called Xfinity (and let me tell you, they will do anything possible NOT to come and check your line), and finally I just sat back. I did get a call from Xfinity which said that they identified some issue with the internet, and that they had resolved it. 

I had 600 Mbps at first, but it went up to 950Mpbs-1000Mbps. I made sure my satellite had a good backhaul, and after that, most everything was just fine. 

I really think it is some issue with Xfinity's coax line. And as I said, if you use Netgear's tools to check your speed, they will be innacurate. Just use Speedtest.net or the app, and you will get better (and more accurate) speed readings. 

I only use the coax line for internet, so I found the splitter, and made sure that the line coming from outside only was connected to only ONE device, my cable modem. All the other connections to other rooms in my house were disconnected. Doing that did improve my signal by a factor of two according to Netgear's diagnostics (it went from an acceptable -8.0 dBmV to a low of -3.7 dBmV on some channels). The signal though, still fluctuates to unnaceptable levels some days above -8.0 dBmV, and I don't even get a signal from channels 31 and 32. 

Unfortunately, I cannot assure you that what I did made the difference, but I can tell you that the signal was weaker in my case before I stopped it from being split.