Well, it were figures, it doesn't matter props can behave in the same way as figures.

Many very old props/figures have the curve dial, but no matter how much I moved the dial it never had any effect until I found one.

And it works fine, if the mesh has enough segments it produce a smooth curve. Curiously again, the curve only worked in some body parts.

In resume, curve works, but I don't know the rules and tricks when it works or do not.

Stupidity also evolves!