Direct output not same when using Alternative input

Hi, I have some issues with the altenative input, when I use it my signal from direct output is différent than when i use the front input.

I tried to choose change the alternative input by defaults but no changes.

Here what it does one the left using front input and on the right using alternative input:

[Blocked Image: https://zupimages.net/up/20/18/7144.png]