Toddler won’t say Mama

My 17 month old has a good vocabulary for his age. I looked up the milestone for 18 months and it says 20 words is average. His consistent, every day vocabulary includes 20-30 words and will even repeat other words you ask him to say (he just doesn’t use those words as consistently so I didn’t count them in the 20-30)

Despite all this, he will not say mama. Sometimes when I ask him to say it, he says baba. But always runs up to daddy saying “daddy”, never to me saying “mommy”. He says “Meow” often so I know he can make the M sound. Sometimes he even says moo. He just won’t say mama.

He’s up to par with other developmental milestones as well. He’s not physically or mentally delayed in other aspects.

Has anyone else dealt with this at this age?