I stutter on specific letters, but I can give presentations and perform plays/musicals with no issues. Anyone else?

I stutter on specific letters, but I can give presentations and perform plays/musicals with no issues. Anyone else? I’ve had this sporadic stutter for as long as I can remember. It’s only when I’m anxious in specific social situations. Now here’s the weird part… I actually have a degree in musical theatre, and I’ve done shows professionally all over the country. I’ve only stuttered on stage like once over the course of 5 years. I also don’t stutter when I’m doing presentations during school, or if I’m forced to project my voice for some reason. Here’s what I cannot do - for the LIFE of me, I cannot say certain words if my sentences begin with “M” words, “B” words, “D” words, and “L” words. I just avoided saying the word “melatonin” in front of my dad because I felt like I would stutter. Does anyone else have no issues giving presentations, but still stutters in very specific situations?