Just in case anyone else runs into the same thing, I was having some issues that I finally sorted out on my own.
I kept running into the following problems online:
Peoples voices would skip rapidly, like a digital glitch, at the beginning of every voice transmission
Races would be extremely laggy, in the sense that the framerate would drop to 10-20FPS
After a bunch of trial and error, I have determined the problem, for me, was 100% remedied by doing a full system reboot. Then as the issue returned over time, I was able to fix it by using the menu and exit option after backing out to the home screen. This has worked about 6 or 7 times now so I would tend to believe it is related to the resume quickly (beta) options since any form of closing the game out completely fixed it.
I have no idea if anyone else experiences this problem but hopefully this will help if they do! Just make sure you manually exit the game once you back out to the home screen.