Anti-Air missiles problem

[Chuva_RD]

From what i experienced it explodes when you directly lock onto flares and just flies through when it gets redirected to flares

Check one of Spook's videos, two shots from 1:00 to 1:20, first missile exploded however it was redirected to flare and made jet burn at huge distance, second missile exploded near jet's engines roughly near place where flares spawns but made no damage. So your theory doen't represent all cases