I recently sent my DJI Spark in for repairs, and received a replacement (not sure if it was new or refurbished?).  


I fly my Spark using the DJI Go 4 App on my iPhone with a remote control.  I had only flown the replacement 3 times before today, all in the past couple of weeks and all from my home while social distancing/isolating.  The 3 flights were all very short, first was 4 minutes, second was 6 minutes, and third was 7 minutes. I took it out again today to fly from my home.  I took off, was hovering above me at about 98 feet, when the screen on my iPhone showed "Aircraft Disconnected".  I immediately tried to bring the Spark down, but the Spark wasn't responding to the remote control.  Then the Spark took off on its own, flying away quickly over the top of my house.  I immediately hit the Return to Home  button, but no response from the Spark.  It was out of earshot and gone.  


My first reaction was that I hope it didn't do any injury, harm or damage when it landed wherever it is.  I'm beyond sad about losing my Spark and upset by this malfunction.  


Has anyone else experienced anything like this?  

Maybe you took off without a HTM update? Did you have the log files?  My suggestion always you fly any drone try to record you screen phone. Its help a lots.