7 month old not sitting up and dragging instead of crawling

Josette

Hi parents! 3rd baby and I've never experienced my other 2 kids not sitting up by 7 months. He does not like to sit up but if i hold him in a sitting position he'll stay for a little while but he prefers to be lying down. He also drags himself around instead of crawling. Has anyone ever dealt with this before and did your baby eventually start crawling?