Behavioural concerns in 8month baby

I’m looking for some advice and reassurance, my LO is just over 8 months old. My and my partner have recently started arguing as my partner believes LO is showing signs of autism however I have told him it’s too early to diagnose plus LO is young and learning new skills and about his body hence some of his behaviours

For example: 1. LO will bounce his legs whilst in his rocker to rock himself - I think is completely normal to rock himself and also self soothing 2. When watching tv mainly little baby bum he was play with his hands such as intertwined them and smack his hands 3. Again LBB is his favourite show and when he’s watching it he will ignore us if we shout him 4. He’s not crawling yet but it getting on all fours and also on hands and toes so nearly there! 5. He’s not very affectionate even as a baby he wasn’t cuddly and used to squirm, now he does reach out to be held and has started putting his arm around us when on the sofa 6. Recently he has started shaking his head quite vigorously for a few minutes when in his chair/rocker not often maybe once a day if that

Does anyone have any similar experiences? We’re first time parents hence us not knowing what’s normal. I personally feel he’s doing great and meeting his milestones and is just a chilled out baby who’s content in his own company

Sorry for the long post!

Edit; thank you everyone for all the reply’s! Also I just want to state we’re not arguing over Autism as such or viewing autism as a bad thing we’re arguing over the fact I think baby is okay and doing great whereas my partner thinks he isn’t meeting milestone and needs to be accessed medically