Distorted audio over headphone problem with motherboard?. mbp2017

Hi guys,

Since a few weeks I got myself a MacBookPro 2017 (the late 2013 one died..). I use the mbp for making music and got this following massive problem.

Playing music over the speaker from the mbp works fine. When I plug in a headphone or other audio 3.5mm kabel everything sounds distorted. Sometimes it starts immediately and othertimes after a few minutes. A few times it helps to remove the jack but it Always comes back. NVRAM resetting and that other thing didn't help.

Is it a software problem in High Sierra or a problem with my motherboard?

Thank you!