I was digging today deeper on this issue because, to be honest, the problem was not totally solved. After spending a while changing things both in the profiler and in logic pro with no success, I came across with this menu in the output section (right click), which allows you to pick among some presets, included "basic home studio" (pic attached). Having chosen this option, the track recorded now sounds exactly the same than what I play in the kemper.
Now I can tell, the problem is solved!