Not waving?

Is anyone else’s baby still not waving? I know all babies are different and develop and their own pace but I can’t tell if he is a little behind or just lazy. At his 9 month appointment his pedi said he should start waving but nothing yet. He doesn’t even try. He will be 11 months next week. He also doesn’t say anything other than dada. He was 3 1/2 weeks early and spent 10 days in the NICU. My oldest seemed to hit everything on time so idk 🤷🏼‍♀️ I am probably worried about it because he is my last