No, the ball is a standard sphere, I only scaled it to 0.02.
Yes it collides with the capsule collider.
When it is spawned I add a force to it with a value of 3 so that it is launched vertically and then falls down.
I noticed that if I reduce the force (to 2.5), the collision occurs less often, as if there is some kind of wind blowing when the ball passes.
The collision occurs both when the ball is launched and when it falls back.
As you suggest I will try with a standard cube and a scale of 1.
To be noted that the collision of the ball with other part of the scene seems to be better, but maybe there is the same kind of issue.
I was thinking, considering there is an offset of 0.01, which is half the size of the sphere, adding this offset to the sphere collider (to the right) and the capsule collider (to the left) may explain this.