Open the Engine.ini file (it will only be here if you've downloaded and opened the launcher at least once before) Locate C:\Users\You\AppData\Local\EpicGamesLauncher\Saved\Config\Windows (or whatever it looks like for you, you might need to the hidden folders like AppData if it isn't there) Most of the guides were good, but lacked crucial steps.
Hey! So I got extremely frustrated that a game I wanted to download was sitting at 10kb/s or some stupid number like that (even though everything else I do runs at normal and high speeds), and after trying all the guides, I finally figured out the actual way to fix it with every detail covered.