I had/have that same thing with my son. He has good grades and enjoys school, but math is NOT his jam. At all. I be tryna explain certain shit to him and steam be coming out my ears. But I've learned that I have to go into it already expecting to get to that point so that when it happens, I'm already prepared for it. You gotta watch your body language, and the deep sighs, and how your voice goes up an octave or two when you perplexed that these lil fuckers don't understand it. Cuz the last thing you wanna do is make them feel stupid or make them feel like you think they're stupid. Then what little confidence they do have in it will fade away and the shit will get worse.