Very slow upload speed

I wonder if this is normal. We have signed up Xfinity Internet service with download speed of 800 Mbps. While the download speed is measured to be reaching 900 Mbps, the upload speed is a paltry < 4.5Mbps. This can be problematic when we have multiple video conference sessions going on at the same time in the household. Is this normal to have such big a difference between download and upload speeds? When we signed up for the service, we were promised to be an upload speed > 10 Mbps. That was the whole reason we signed up for the 800 Mbps service level. We were seeking a higher upload speed. The download speed of 200-300 Mbps would have been sufficient. Is there some problem, or is it what Xfinity service provides? I was having a hard time reaching an agent in person these days.