Hello everyone! My child has never wanted to lie on their stomach since…

Hello everyone! My child has never wanted to lie on their stomach since birth. Now we're 7 months old and they haven't even crawled yet, not even on a tummy time mat. They don't even want to lie down, they want to sit in a stroller, on a children's tricycle, they don't sit themselves, but if you put them in a sitting position, they sit straight up holding the back. Are there any kids who didn't crawl right away and started walking? Has anyone had a late crawler? We have done two rounds of massage for dysplasia.