AtennaTracker issues/question

In trying to get an antenna tracker to work properly I am having to set the P gains very high, 8 ish to get it to move. One thing I notice is in mission planner the target line is always correct but the tracker doesn’t always point in this direction.
I thought I would take a look at the code and see if I can make it work a little better… seems pretty simple… current position and target position… seems you could get the AT to point at the target with just those two points and using servo limits. (Doesn’t seem to be doing this now, the two lines don’t always match)
I can build the other targets and flash and everything seems to work fine. (flown a custom firmware built arduplane)
But when I build the stock AT firmware it doesn’t always work and seems to lock up on me. Am I missing something in building the firmware?
And should the P gain really be this high?
I am using Hitec HS-785HB servos that are geared for extra torque.