I dont understand my stutter

I dont understand my stutter Scrolling through tiktok, ive found many videos where you have to read a speech like teleprompter style, and i always nail it. Really, i sound like an expert public speaker. No stutter at all. But in my everyday life i do stutter. Its not a stutter where i repeat words, is more like i get stuck. I can have normal conversations without a problem but you would definitely notice some kind of stammer. I also get stuck when people ask me something and i have to respond immediately even if its something i already know the answer to, like my phone number or what do i do at my job Why do i speak perfectly while playing along with those tiktoks?