T3 timeouts will cause a brief drop every time they happen, especially in terms of upstream data (so on a video call the person on the other end will see you glitch or cut our for a moment). Your downstream power levels are at or slightly above the recommended maximum, but your SNR is quite low in comparison. You also have a very wide variation in downstream power between the 800/900 MHz band and the 400 MHz band. My gut instinct is that there is a bad or unnecessary amplifier somewhere in the mix that's amplifying a lot of noise along with the signal. The wide variation between power on upstream channel 1 and the other upstream channels also points to something on the line that's affecting frequency response. Hopefully connecting directly to the drop fixed it. If not, there may be something in the plant that a Cox tech would need to look at.
