Hey Malcolm!
Having had the same issues with pan I am pretty certain that you need to adjust the center of your pan servo in the menu. In stabilized mode Picloc will keep heading, therefore servo trimming is nonrelevant but when you deactivate it, the servo has to be trimmed to remain centered.
I don't know how you achieved that 360° servo, I replaced the poti with two identical resistors, but as you might know, there always is a tolerance. That tolerance probably is responsible for a shift in the center position. After readjusting it now keeps its position whether in stabilized mode or not.
Having had the same issues with pan I am pretty certain that you need to adjust the center of your pan servo in the menu. In stabilized mode Picloc will keep heading, therefore servo trimming is nonrelevant but when you deactivate it, the servo has to be trimmed to remain centered.
I don't know how you achieved that 360° servo, I replaced the poti with two identical resistors, but as you might know, there always is a tolerance. That tolerance probably is responsible for a shift in the center position. After readjusting it now keeps its position whether in stabilized mode or not.