Hello EdMercer, thank you for your reply.
I´ve tried combinations between fat and narrow flags, but the problem persists. I have almost certain that i am doing something wrong but i dont know what it is.
Currently, i am not applying no force at all in the ball (like phent_addcentralforce), just pushing and carrying the ball with the player movement and rotation (like in a foosball game) via c_move and c_rotate.
When i push the ball a little faster, sometimes the player seems to penetrate the ball and her trajectory is unstable.
In other hand, sometimes when the player collide frontal with the ball (applying a rotation), she passes through him.
i am using 3dgs 6.31.4 comm, with enable_polycollision = 1 (default)