Slow Download Speed, Upload Speed is Almost Zero

I've had a reoccurrence of an issue I had about 2 weeks ago. The issue is that suddenly the download speed drops (I pay for gigabit service) and upload speed goes to almost zero. The download speed drops to about 450mbps (when it's normally at least 950mbps). The big issue is the near zero upload speed. Normally I get around 40mbps. I just spent a frustrating evening using the automated Xfinity assistant, then finally getting an agent on the phone who was unable to help. Ultimately, I was passed to a supervisor and all he was able to do was setup a technician appointment. It seems odd to me that this same problem that I had a couple of weeks ago was not able to be resolved remotely by correcting a problem on Comcast's end (i.e., there weren't any problems with my equipment). I pointed this out to the supervisor agent, but he didn't seem to listen or investigate what the corrective action was when I called about the same problem a couple of weeks ago.

On a side note, the virtual assistant is not robust at all, and its simplicity causes a lot of frustration for customers. There should be an easy option for customers to exit out of the AI based system at any time and revert to a live agent. In my case, the live agent may not have been able to solve my issue, but I would have wasted much less time.

As of now, my issue is not resolved. Any input would be greatly appreciated!