My wife's name is Nada. I pronounce it nA-da and siri says nah-da. If I don't use the siri pronunciation it won't find the contact. Took me a while to figure out that work around.

I have a similar problem with my car's native voice recognition. But Siri gets both the recognition and pronunciation correct. I wish my car had CarPlay.

Maybe it's language-dependent? Dutch isn't spoken by as many people as English for instance, could be the algorithms just don't work well enough yet.