While it is less than 10 feet from the WiFi router it is impractical to hard wire it without running an ethernet cord directly across the room. I’ve done WiFi downloads on this Xbox on my brothers xfinity WiFi connection and the download speeds were much faster
Well, you're not at your brothers' place.
You're gonna have to figure out where the problem is - if you connect the XBox via Ethernet and you get normal speeds then you can elminate the Comcast modem/gateway as the problem.
BTW, I have a gigabit connection and downloading from the Microsoft Store was slow as molasses the last couple of days, probably because there's a massive sale on games ATM and people are downloading like crazy.