Xfinity Internet Upload Speed Capped at 40 Mbps. Should be around 200 Mbps as part of 1200/200 internet Plan.

Hello. I currently have 2 locations on my Xfinity account. At my Homewood, IL location I have 1200/200 internet, with speeds exceeding those numbers. At my Tinley Park, IL location I also have 1200/200 internet, with download speeds exceeding 1200. However, my upload speeds are capped (throttled) at 40. Between September 22, 2023 and November 15, 2023 my upload speeds at the Tinley park location were averaging 240 Mbps. Since November 15, 2023 however upload speeds at my Tinley Park location have been capped at 40 Mbps. After numerous calls to Xfinity Tech Support over several months, I was told to update my modem from XB7 to XB8 to no avail, and numerous tests were run, my modem reprovisioned, and a tech visit yielded no issues, but still to this day my uploads max out at 40 Mbps. Please, will someone explain what is going on? Thank you.