Problem with normals, smooth / autosmooth an object

Hello, I’m trying to use a model that someone gave me and I’m having problems with the normals.


This is the model.
I want to smooth the vertical faces of the cylinder, but when I use autosmooth they stay flat (I tried with every angle from 0º to 180º)


I tried to merge the vertex because maybe the faces are no-joined but it’s not the case.


I tried with normal smooth and those faces looks good but not the other part.

imagen
I checked the geometry data and there is nothing there.

I also tried a lot of normal’s menu options without success.

I can’t divide the geometry in two objects because it’s for a threejs project and they ask me for a single geometry object.

Do you know any other trick or how to fix it?

Thank you.

Try this after you select smooth:

Screenshot 2023-07-04 055524