RESOLVED:
I found the answer to my question myself: there is no way to make the linetrace follow the mouse path when the camera is set as a reference.
It was all wrong from the start. Here is the correct blueprint if someone like me wants to click on an object and interact with it and that the linetrace following the mouse path.
Thank you for your help and I apologize if I asked the wrong questions, I still have a lot to learn.
