Cubase 9.5 AI with Yamaha MG12XU recording issues

Hello everybody!

A friend of mine ask me to configure his little studio setup. He has Cubase 9.5 AI with the latest update and a Yamaha MG12XU as an audio interface. Everything works fine except for this issue: he has a drum track made with GrooveAgent and he wants to record a guitar track. But I don’t know why, the audio track records the output of the drum track as well ! I tried to configure the routing but nothing seems to work.

Has anyone had this problem? How do I fix that?

Thank you in advance !