6 months old baby

Hi Momma's! A first time mom here I just want to ask some advice. My son is now 6 1/2 months. he is very Happy,babbling baby he always smile at us,hitting his milestones and loves playing toys but lately when I call his name he doesn't turn around sometimes like when I call his name he turn around and look at me and then when in call him again he doesn't look at me.l'm a bit worried because this is not new to us because before he never ignores us.

I need you advice Mommy’s ❤️ Do I have to worry about it?

Thank you