You say that you’re fine with MS Teams and gaming. It could be because your brain is visually engaged while speaking during these activities, whereas when you use the phone, you go off into a vague headspace that allows your brain to spend more cycles focusing on your stutter. In other words, your stutter might be better when your brain is engaged visually, so maybe trying to actually focus your field of vision on something while talking on the phone will help. Try watching a music video while on the phone and see what happens. FWIW I used to HATE talking on the phone because of my stutter, but these days it doesn’t phase me at all. I don’t actually do what I just suggested, but it was something that I gave considerable thought to a few years ago when I was actively trying to decrease my stutter. Over time, my stutter has greatly decreased to the point where I don’t think about it much anymore and just live my life.