I drive a Kona electric in Spain and I use the remote HVAC start basically every day because in temperatures at 30⁰C plus it's a godsend to get into a pre-chilled car. The app always works but with a minor quirk. I send the HVAC start command and after about a minute it ALWAYS comes back and reports that HVAC has failed to start. But if you then request a status update it will show 99 times out of a 100 that the HVAC has indeed started and, sure enough, when I get back to the car it is lovely and cool. But mostly, after getting the HVAC fail response, I just resend the HVAC start command again. Why? Because it almost immediately responds with a HVAC start success message and this is actually quicker than doing the status update to check. So it always seems to work ok for me, but with the quirks as described. Hope this helps. BTW, I thought a new Blue Link app was due out soon?