1% of advertised speed !!!

Whenever I test my upload speed it is almost always a paltry 1Mbps, just 1% of the advertised 100Mbps that I’m paying for.  Only rarely I do get 100Mbps for a brief test.  This is way too slow for everyday use of Cloud services and file transfers. I’ve heard the same complaint from neighbors.

Download speeds are consistently good, around the 300Mbps available in my Xfinity plan.

In an attempt to solve this problem my local Xfinity store swapped out my existing Xfinity Modem for a new one (XB8-T) and I still have the same problem, I only rarely and intermittently see 100Mbps upload speeds.

I’ve used Xfinity Assistant numerous times via a web browser on my PC, only once did it acknowledge and correct (briefly) the low upload speed problem.

Clearly the physical connection to my home is fine, proven by the consistently good download speeds.  I don't think I need a tech to visit my home.

Any ideas on how to get effective help from Xfinity?

Thanks