Ecu disconnects when I load a new map

I have a plug and play haltech platinum pro for a genesis coupe, when I connect the Ecu to my computer it automatically downloads the base tune for the car. Whenever I try to switch to my tune file it disconnects the ecu and the process repeats if I try to connect again. Any ideas why?

Maybe your car has a "keep-alive" relay to power the ECU and allow the ECU to remain powered after the ignition is turned off. Maybe that get's turned off while flashing. What does Haltech say? Do they suggest some kind of jumper for the relay when re-flashing?

I had the same issue with that ECU and vehicle. I suggest contacting Haltech support.