Suspected over saturation of network causing intermittent lag spikes and packet loss

Been tracking network issues I've been having for over a month now and it hasn't gotten any better.

Have talked to Comcast 3 or 4 times already.  Talked to modem manufacturer to confirm my last modem was performing as expected and ruling out equipment issues. Even went one futher and bought an entirely new modem since Comcast INSISTED we needed to to fix the issues. We now have an ARRIS SB6183 and an SB8200.  Issuses happen on both.  Plugged into router or directly into modem.  Tried new ethernet cables as well.

But again, it's intermittent, so it's the perfect problem to blame customers for instead of letting us talk to actual techs and not CSRs since their script lets them push the blame onto us every time since their 2 second test miraculously always says it's fine.  We run pingplotter and have tried other things like speed tests when it happens and there's always noticeable latency spikes and packet loss along path and at destination.  Speed tests download speed spikes up then slowly drops like it's throttling our connection during these times too where we also notice video buffering (pausing videos before testing of course).

We had this same problem a few years ago and after months of documenting and somehow getting the info to email the data to the regional manager was able to finally get a tech to monitor our node and find out the issue within a day.  Turns out the node was overloaded from all the new customers being put on it due to all the apartments being built around where we live. They told us they upgraded the node after this and voila, all the problems disappeared like nothing was ever wrong. 

I suspect it's the same issue this time as well since way WAY more buildings have gone up since the last time this happened and wish someone could just monitor our node and let us know if that's what it is since we've tried literally everything else and it's been a persistent issue for months.