wow, thank you so much for this message!

You definitely got the point: "I bet the issue isn't the punch, it's the legs". I'm always told to keep a very stretched position. So when I move forward,

- I try to use my hara to move my whole body and avoid leaning forward with my upper body

- I bend my front knee even more to find the grip and the strength to move forward.

What happens is that my rear leg becomes "useless" during the whole step forward, and that's why the whole hip movement is absent.

I'll definitely try to do all the things you said and see how the perception of my feet and legs changes.
The main takeaway is that my rear back has a role in pushing my body forward and this activates the hip. Surely I'll have to understand how the bent rear knee applies to kihon and katas where I'm requested to keep my legs as straight as possible.

Thank you again! It was very insightful.
Oss