It sounds like your stick may be having a bit of an issue. Have you tried using an entirely different controller to see if the same issue applies? If you've tried another controller and the issue persists, and you've done the whole crap about cache clearing/license restoring, then you may want to uninstall and reinstall to see if it was just a file corruption. There's a cooldown on sprinting after you've just finished sprinting, but the only things that should stop you while you're sprinting are if you run into something, you double jump, you reload, you let off holding the stick in, etc. It shouldn't just randomly stop for no reason.