I never encountered that but I've seen several discussions about it. According to some posts, you have to stay still, don't press any buttons, until the prompt 'z' shows up- only then press z.

Check this post, for example:

https://steamproxy-script.pipiskins.com/app/3278760/discussions/0/4626979791702122046/

This is not help at all trying to deal with the fine mission but every time I keep doing it, I don’t know what button to press because I keep getting stabbed no matter what I do and you need to add a button, pressing guide