Mentioning the hamartoma and then dropping it later was such a major plot hole

They mentioned that Michael’s mother died from a hamartoma, and then we saw Michael having nosebleeds and collapsing clearly meant to hint at something serious, like a genetic condition. It was obviously meant to make us think he was dying too.

But later on, none of it gets followed up. We even find out that Michael’s mother is actually alive, and yet there’s zero explanation for Michael’s symptoms, the supposed illness, or why any of it even mattered. It’s like they just dropped the whole storyline completely.