A picture paints a thousand words, a Project paints a thousand pictures.
It would be much easier for someone to help you if you provided a Project file. Otherwise they have to recreate it themselves from the text you wrote.
I see what you mean. The slur attaches to the wrong voice. Easily fixed in Engrave mode, of course.
It’s not actually attaching to the other voice. Collision avoidance is pushing the slur above the staff. If I recall, you’re using SE? Not sure this can be solved without Engrave mode.
EDIT: If you don’t mind an under slur, select the TAB Slur, open the Properties Panel and change the slur direction.