Because it's cannot move like normal i setup the end point at 100%but it can move just 50-70% and won't move back to the position. i do reset and update firmware but it still happen. I read some article of fs i6 they got a same problem with me and when they do calibrade the problem is solving.
Have you tried just bare servos? Measure the movement, see if it does equal movement with stuff out the plane.
If it’s fine out the plane then you know the linkage on the elevator is the problem. Start by checking that the linkage stopper, if used, is moving freely. Then check the hinge is free to move, if you put too much hot glue in the himge bevel it can stop the smooth movement of the servo. If the hinge moves freely and linkage is free moving then check the position of the linkage in the servo horn. Nearest the plane = most movement. Also the position of the linkage in the servo horn, further out on the arm = more movement.