Can't cut the end of my stroke

Hi,

Beginner here, I want the end of the stroke to be flat and in alignement with the text.

I tried to convert it as a shape to use the scissors but no sucess, it doesn't want to become a shape. Then I tried outline path and minus front but since it is not a close object, it does substract what I want be create a new stroke closing the path.

Is it because of the gradiant ?

Thanks in advance !