Upgraded to new Xfinity WiFi gateway with free equipment upgrade offer. After install, my upload speed is less than 20 mbps.

Hello, yesterday I installed the new Xfinity WiFi gateway using the Xfinity app for new equipment. Everything works fine except for the upload speeds. It now gets only about 20 mbps . My plan is the Superfast plan, 800mbps down and 150 Mbps up.  Can you check if the modem speeds are correctly provisioned. Thank you!