I use GS Pro about 10 times per month.
A couple times out of every ten: I plan the mission (I only use 2D and 3D map) and attempt to start the flight.
GS Pro goes through the pre-flight checks, everything is green checks, and my P4P takes off but just hovers around 8 - 10' in altitude. (Most are planned around 150').
When this happens, I can't manually left-stick up and increase altitude or use the directional right sticks.
My only option is to decease altitude with left-stick and land.

This has happened a couple times consecutively and then my work around is to land, fly to rough altitude with DJI Go, kill the app, reconnect with GS Pro and start the mission while already in flight. While I hate having to do that, at the end of the day - I guess it works.

BUT the question is: What could be causing this erratic behavior from GS Pro?

Sad we haven't gotten an answer.  I have this problem almost every time I fly which is about the same as you - 10-15 times a month.   I also cannot resume a flight when I land to change to batteries.  I have to now close the app and reopen it, then it will resume.

I’ve had this happen to me several times. I found it was an error with the dji go app obstruction  avoidance enabled it makes the gs pro ap glitch out. What I have to do is dis able the obstruction avoidance before connecting with the gs pro app. I hope this helps..

  15#

one question I have that I can't find an answer to.. So I’m flying a M600 pro using go app and gs pro. I did a flight on my local airport runway using waypoints. Home position logged the drone at 100 feet altitude. The runway gains 40 feet in elevation over 6000ft I have 6 waypoints one at each 1000ft. The drone stayed at 100ft while the runway got closer to the drone. My question is this. If I add altitude to my different waypoints will the drone gain altitude during the 1000 feet between each waypoint, or will it be a stair step. Fly at 100ft hit way point and gain altitude and continue to the next? Thanks for your help in advance

Sometimes in a Waypoint Mission you should change speed in "Auto" Mode instead of "Manual"

djiuser_ig7FAJ0g4Ssb Posted at 8-10 08:01
Sometimes in a Waypoint Mission you should change speed in "Auto" Mode instead of "Manual"

since posting my last comment i figured out the majority of my issues. I did find out the drone is able to interpolate the way points so that is very helpful with the flight description i posted above. the only things ive had to enable or disable has been the max flight distances on both, DJI go app AND DJI GS PRO app.