Angular Wildcard Routing Doesn't Always Work

Question

Using Angular 4, I have the following in my route collection:

{ path:"**", //wildcard component: NotFoundComponent, } 

and if I try to go to http://127.0.0.1:8000/xxx , I will correctly go to my NotFoundComponent, however, if I try to go to http://127.0.0.1:8000/xxx_(xxx) I do not . I tried various permutations

 { path:"**_(**)", component: NotFoundComponent, }, 

placed in front of my lookup pattern, but they also didn't work. Thoughts?