I recently purchased my P4 and am getting the hang of it. But i have a question/concern. Whats the landing speed on the drone when using the RTH function. On one of the landing attempts, at an altitude above 200ft, it came down pretty fast, which i had to attempt to slow it down and was partially successful and it did a touch and go. Note: I recently installed the an after market foam on the landing gear and gimbal protection. On some landings, its came down slowly and softly, and others it came down pretty rapidly. Are my sensors off? Also, I have been seeing an error on screen about IMU error and that the max altitude was reached or something. It informs me to call DJI customer service. Ive let it warm up as instructed before each flight.