Thank you for the answer. Yeah, sorry for the incomplete info., it is godot 3.1.
I am connecting the signal using a function like:
print("mouse entered KinematicBody2D")
Its true there are no PhysicsBody2D objects, but all of the classes inheriting from it (Kinematic, Rigid or StatyicBody2D) seem to have the same problem, unless mouseentered is not suppose to work in the same maner as for Area2D. I could add an Area2D child to the PhysicsBody2D classes but, what is then the purpose of the mouseentered for them? Is it used in a different way?