That doesn't sound like it was the same thing at all.Same thing happened to me over Lemon Bay, FL. All of a sudden, without any input, she landed in the water. It appeared to be a controlled landing and there was nothing I could do about it. I was about 40 feet from the drone.
The OP's drone didn't land in the water.
If you want to find out what caused your incident, post flight data.
1. Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it provides and someone might be able to analyse it and give you an understanding of the cause of the incident.
or
2. Just post the .txt file here
or
3. If you use Airdata, you can view the flight data on Airdata and post a link for the Airdata report