I have had a couple instances where I lost control of my Phantom 4. I had posted over on another forum but today learned this is likely a little more targetted to the kind of help I need.
I bought my Phantom 4 used several weeks ago. It flew fine for the first 8 - 10 flights. I flew it around my shop which is in an industrial area as well as a nice spot outside of the city which I live in. So the issue seems to have developed during my short ownership. I have not crashed it. I have had 4 instances of this loss of control. The three previous times which I lost control could potentially be explained by my being around metal or other interference causing items. I think that today I was not launching from a spot at which anything could have caused interference. Maybe I am wrong about that. This Phantom is scary when I am not able to control it. I also have a Mavic Pro and Mini. Neither have had any problems at the spots where I have had trouble with my Phantom.
Today I had two flights. The first was about 20 minutes then I landed at 22%, changed batteries. The flight was great. THe Phantom performed really well. The second flight, I launched and within two-ish second moved the right stick to move the Phantom a little farther away from me. I sure wish I had a GoPro on my head to video what happened. Like before, it shot off in a random direction without any input to move it. My control problem started at about 1m, 9Sec in to the log. I started trying to put it down right away. it would go down then lurch upwards repeating that. I put it into sport mode to turn off obstacle avoidance to attempt regaining control. It made no difference. I also turn avoidance off then went back to P mode, same thing, down then up. Eventually after about two minutes I got it on the ground. Lucky that there was not hard landing impact. I can see that in the flight, long after I lost control, there was a huge signal loss. I noticed signal strength lower than I expected in my first flight as well.
My Phantom has a Maxxuav DBS Phantom ITEllite DBS02.22 and no other mod.
First Flight today which was good (for reference) https://www.phantomhelp.com/logviewer/4DP116XM0OJQ0VHDLL65
Loss of control flight: https://www.phantomhelp.com/logviewer/OY8JLRG4J928KG1V56PN
Thank you very much for any help identifying my issue.