Sitting without support milestone. 😞

Karine 🌷 • Mom of two handsome boys.💙 English is not my native language! Please excuse any mistakes.✌🏻
My son's still not able to sit without support for more than like maximum 1 minutes. 🙁 and I feel like he's late for this milestone when I see every babies on this group, sitting like champion, for long period of time. Are there any tricks to help him sit without support? He does the tripod but he always falls foward or on the side.