Upload speed 7x slower than what I am paying for

I unfortunately feel that I am out of options but to let others know about my current experience.

I must have spoken to 10 different xfinity support agents, and I either get transferred after 30 minutes of (the exact same) troubleshooting with every other agent, or assured that 'my issue will be resolved', and then offered to upgrade my subscription to a faster speed. No...I want to get the speed that I currently pay for!

I pay for 1000/150 currently (bay are, CA). My account page shows this plan with exactly these numbers. I use my own modem (ARRIS Surfboard S33 DOCSIS 3.1) and pay extra for unlimited data.

I get 1000 download speed consistently - this is the good news!

I get no greater than 25mbps upload speed, most of the time 20mbps or so. It appears to be a cap in speed, or some error in provisioning my plan for my address/cable hookup.

I am tired of chatting with xfinity agents with no resolve, and have no other options for cable or fiber internet in my community, so posting here to get any feedback or attention possible.