Thanks to both of you!
I actually didn't know how to use the front noise gate that removes the him of the guitar. My guess is that that noise got filtered out in the beginning, but at some point it reaches, amplified by gain, normal "picked note level" and goes through the 4:1. Pretty disturbing..
Now that I have adjusted the front noise gate for each guitar in each song, it works perfectly fine.
Best regards and thank you,
Manu