I barely stutter when I'm in a heated argument

I barely stutter when I'm in a heated argument It's the weirdest thing. I don't have anger issues but if someone warrants me to raise my voice, sometimes I don't even stutter. Even my brother commented how I never stutter when I'm calling out bullshit in more of a harsher tone. Does anyone else do this? I wonder what would cause something like this but yet I still stutter my ass off when I describe how my day went. I guess maybe there's little-to-no anxiety when angry? My brother said I should be angry more often, lol.