Jerky servos through manual mode APM 2.6

Hello, I have APM 2.6 on my Mako. For some reason the servos are kind of jerky, not smooth in the operation when I move the sticks in manual mode. It still flies good as is. However when the servos are plugged directly to the rx, they run much smoother. I do have a power module and no jumpers on the APM. Any tips to help the jerkiness?