Again, if they’re endearing they are not real flaws
let’s use Roy Mustang from FMA, he’s a charismatic leader, good looking and one of the strongest characters in the story. His flaw is his cold blooded attitude and thirst for revenge. His flaw is not championed as a good thing, instead it is made very clear that it is not only detrimental for his goal it also makes him as bad as a villain(he’s literally drawn like one)
that’s how you write a flaw