Paying for 1.2Gps Xfinity plan only getting 250Mbps

Recently changed internet speed from 1.0Gps to 1.2Gps, but only getting around 250Mbps at the PC. PC is custom built with a 2.5Gps ethernet Intel card/port. New G36 DOCIS 3.1 modem (Xfinity approved) Tp-link 10Gps router with 2.5Gps ports. Just had the Xfinity Tech out here 12-28-2022, tested the line from street - he was getting 930Mbps+ on his little meter device. While he was on-site, we tested side by side from the modems 1Gps ports, and from Xfinity speed test website - he was getting 900+Mbps, while I was getting just 200Mbps. Just doesn't make sense. Every piece of network equipment I own is capable of over 2.5Gps; including CAT6 cables. The runs are less than 50 feet with no other connections. Fun fact, on 12-24-2022, I hit 1.4Gps, but just that one day, 12-25-2022, back to 250Mbps. I prepared a table below to showing my speeds since switching to 1.2Gps