Try this:
One of your computer's devices (such as joystick, or even certain gaming keyboards) is causing this behaviour. Disable your devices, then reactivate one by one until you find the problem one, and leave that one disabled.
Reference: Certain Human Interface Devices can mess up directional input, for instance locking it as permanently up and to left. In my case, it was “HID-Compliant Consumer Control Device”.
-It started working after unplugging and replugging in my keyboard after a reset. (Turns out it was a small gaming keyboard)