Evo 1 Drone disconnecting all the time

[Rorysee]

Hi folks. I haven't flown my Evo for a few months. Twice now as I fly the drone away from me say 10 meters altitude and 20 meters away the drone loses connection and returns 10 meters above my position and runs the battery down then lands. during this, I have no control over the drone at all. I did reinstall the last upgrade = EVO _ fwv1.5.8.bin on my controller and ran the batteries to update. I don't know if this is even the right install as it's not very clear on this forum from the upload page. I haven't flown the drone yet after the new install. what else can I check to sort the problem out? In the past I had no issues and flew 500 meters high and 2 km away no problem in the past no issues