If you have Win10, then Microsoft has installed some buggy X-Box App on it which has been causing sluggish PC hardware inputs and possible game stutter.
This was regularly happening to my rudder pedal inputs while playing DCS. Found the answer in a YouTube DCS search, of all places.
In case you didn't see the link in the DCS thread, here's how to remove it:
http://winaero.com/blog/how-to-uninstall-and-remove-the-xbox-app-in-windows-10/
Be aware that MS will likely re-install this App in some future Win10 update, as it's reportedly happened once to people who removed it before. So you may need to keep doing so on occasion. ::)