Almost 7 months but still not rolling

I didn't worry at first because each baby is different, but I'm looking through my gallery and my first was crawling, rolling, pulling himself up on people to stand at this age, his first steps was at 8-9months.

My LO has been different from his older brother from birth, his a unicorn baby, always happy and content, does have his days like all babies do but his a dream. Anyway, his always hated tummy time, even on my stomach, his whole body tenses, legs and arms go up like his skydiving and he cries. When lying on his back sometimes he curls his body to the side to see behind him but doesn't attempt to roll, at night he puts himself on his side to sleep, never once woke up to him on his belly, he can comfertably roll to the side or back to his back. His only recently started sitting, still needs to be assisted because his balance can go within minutes and he hates to be lied down in the stroller, he wants to sit upright and pulls himself forwards to see more, also he can pretty much stand on my lap, loves to jump as I'm holding him, my partner wants to get a jumperoo for him but I'm worried it'll delay him even more, I don't mind holding him as he jumps away. I got him an IKEA highchair as I thought it will help him learn to be stable as its nothing fancy, but it works for a minute or two then he slides to the side and slouches, cries to be corrected back upright so we haven't properly started introducing solids, maybe a rusk or a Ella's kitchen melty stick here and there.

Does all this sound normal for a 6-7month old (he turned 6 months at the beginning of this month), because compared to my first who was crawling already and pulling up to stand on everything himself, following me room to room, my second is soo much more slower and my first did have a jumperoo from 4 months wihh a pillow under his feet to reach because he was just so crazy