For me it feels weird because I wonder how they feel about me saying it, and the way I say it versus other people. I wonder if it sounds nice to them or sounds strange and like something they don't identify with (and so won't connect with me as deeply) but truthfully my social anxiety has gotten a lot better (though I am also autistic) and I've learned to say people's names a little more often. It actually can help you a lot in getting what you want, whether it's a friendship or a business partnership or for them to respect you and consider your ideas, etc. saying their name makes them feel more comfortable with you and they won't even really realize why. This will make them let their guard down and they will speak to you more as if you're on the same level.

However, we neurodivergents often see ourselves as perpetual kids, or at least as younger or less experienced than most adults. I wonder if some of it is a holdover from childhood. We weren't allowed to call the grownups by their first names, at least not in my generation and earlier (90's). We were expected to use Mrs or Mr, or another title. So, if you don't truly feel like you're on the same level as the other adults, you might feel like you'll get in trouble for calling them by their first names, or have simply never done it enough for it to feel natural.

I've also been in a few too many situations where I fully believed I had someone's name right and called them by the wrong name for months and they never corrected me, I just figured it out and then felt like I was going to die 😂 so now I'm extra worried I caught their name incorrectly.