Why is the AIM-7M so prone to self-detonation

In addition to the fact that the enemy is flying directly at you, whether it is tail chasing or intercepting the aircraft, the AIM7M often self-detonates within 5 seconds after launch, why is the current top radar missile in the United States so rubbish?

Please have time for the Warthunder planner to test fly the F16 and see how ridiculous the 7m missile you designed!