What causes a stuttering?

What causes a stuttering? I know it's a thorny topic, but what's the reason for our stuttering? I tried to find a solution in more than one place, more than one website, ChatGPT, etc., but I didn't reach a single reason or a clear reason Based on my personal experience, I have been to two psychiatrists in the past. One of them told me that the reason was upbringing, childhood problems, child abuse, hitting, lack of love or emotional support. The other said that it was due to genetics and family, WHAT U THINK?