07 R1 shifting issue

He guys. I have recently been experiencing a shifting issue. Sometimes when I try to up shift beyond 2nd gear it does not shift up in gear unless I lightly tap down on the shifter lever to reset the shifter then I can shift up into the next gear. But I have to repeat that for every gear. It acts like it sticks up and wont let you shift up in gear unless you push the shift lever down to reset it. And every once in a while I have to do the opposite to down shift. As in lift up on the shifter lever a little bit then I can down shift. Now just to be clear it doesn't happen all the time. But it is happening more and more often. Has anyone experienced this before? If so what was the cause of it? a shift rod spring? I looked in my maintenance manual but it doesn't give any trouble shooting reasons for this. Thank you for your time.