Okay, i already figured it out, the problem was that i was approaching this with a sound engineer's point of view. normally the sends are on the top and the sends are on the bottom. i made a preset patch with returns blocks and tested all the inputs, and it works flawlessly like it should! thanks for the replies and the support!
Ladies and gents! since a week ago i am a proud owner of a Line 6 Helix! but when i was fiddling around with the internal routing, i noticed that the first and third return are not functioning, the 2nd and 4th are working (i tested this by playing music with my phone through a mini-jack -> 6,3 adapter.) Is my hardware faulty? or is it a internal/software setting that must be adjusted? i hope you guys can help me out with this issue! with best regards, Milton