HERE3 GPS Not detecting satellites with latest firmware

Hi, i am new to ardupilot. I build drone as a college student and participate in competitions. Recently i was building quadrotor, but the GPS was not going in lock mode. It was showing Satcount=0 on mission planner. I tried going different open places, but still no luck. Then a senior told me to change firmware to a older version. I changed it to 4.0.1(stable) and it immediately started working. Can anyone here help me understand why going back to an older version of firmware, fixed the GPS error?
(I am using pixhawk cube orange)