I recently built a DJI F450, and I have flown it 3 times. the biggest gripe I have is that in GPS mode, the drone tips to the left ( its like I pulled the stick all the way to the left on my transmitter) and it goes straight that way. Sometimes it corrects it self but then its a continuous problem, right now its at a point where stable F450's on youtube are merely a legend and I think I will never be able to achieve it. I started up in manual mode today, and it was actually much more stable than normal. I only had it a few feet off of the ground but it stayed that way and as soon as I flicked on the GPS atti, It rolled to the left and continued to go. I felt that the props were loose, so I tightened them up by a lot, hopefully this helps. But does anyone have ideas on why this might be happening? Thank you