They are not worse at home. They are safe at home.
The teacher says your child is calm, polite, no trouble at all. Then they walk through the front door and fall apart. Shoes thrown across the room, tears over the wrong cup, a meltdown over a sound their sibling made. You describe this to people and they look at you like you are exaggerating, or like maybe the problem is you. It is not.
Here is what is actually happening. Your child is masking. All day they suppress their natural responses. They hold eye contact that costs them, rehearse what to say, and copy the kids around them. All of it to appear like everyone else in a world not built for how they work. Researchers call it camouflaging, and it is exhausting. By the time they reach the one place they trust completely, which is you, there is nothing left to hold the mask up with. The collapse at home is not bad behavior saved up for you. It is the armor finally coming off.
This pattern is one of the main reasons children, especially girls, are diagnosed late or missed entirely. A child who performs well enough to look fine can struggle for years without anyone outside the home seeing it. You are seeing it. That you noticed is not a small thing. It may be the thing that changes their whole story.