This gonna sound weird, but me and my logopedist found out that when I say things that I don’t prepare or didn’t think through before I actually said it, every singe word is going perfect. We also found out that I need a planner to get some rhythm in my life. When things aren’t unexpected (dinner every night at the same time etc) my stutters also reduce drastically. Edit: also when I sing along with a song that I know, I also don’t have any stutters.