Random Spike in Upstream Levels Causing Frequent Disconnects.

I have a Netgear CM1000 as my modem. For what feels like forever, my service has had constant upstream issues. The upstream levels will randomly spike, causing severe packet loss and frequent disconnects. I have had a few techs out to fix this, some not even knowing what the word "upstream" means, and none have helped. My modem error logs read "Dynamic Range Window Violation" and frequent T3 timeouts.  I even installed a amplifier with active return in order to help lower the upstream levels, but that has not helped.

Example of Current Upstream Levels (w/ active return amp)

Example of Current Upstream Levels Spiking (w/ active return amp)

Example of Past Upstream levels spiking (pre active return amp)