2011 engine stumble when shifting

Hey folks my JK after 34,000 trouble free miles just developed a slight stumble when shifting. It seams more noticeable a in higher gears like 4th and 5th. It is definitely an engine issue, it makes the shifter vibrate for a second when it happens. I tried to lug it way down and then ran the engine up to 4,000 rpm,s and can not make the engine act up. It just happens on normal shifts right when you let the clutch out for a second. Any input will be appreciated