Find your tribe in a Sea of Creativity
One idea that I can't get out of my head is that maybe Matakara doesn't feel completely comfortable going to his friends' houses, because seeing them interact with their families makes him jealous and he feels bad about it. This also happened when visiting Arajin when he was younger, seeing how loving his mother was towards him (something that is not difficult to imagine) to that we add that surely given his background he must feel an almost instinctive distrust towards adults, especially parents, there being few exceptions to these.