Legs move improperly

1557291057

My 6 legs spider robot moves improperly. The problems seems come from the leg 4 and 5. While it go forward, the leg should lift up, move forward and put down. However, they don't lift up the leg but keeps go downward and pointed inside the body. Symptom is found only the leg 4 and 5. I have checked the sketch and looks normally. Is the servos problem?

1501915115

One: check if the uploaded code version is correct;
Second: check whether the two servo connections of the circuit are correct;
Third: You can try to replace a steering gear to try it out. Is it the problem of the steering gear itself?