While you do get the honorary title by doing that questline, there is no actual "title" obtained that you can put on your characters.
There are only 3+1 actual titles obtained from the base game quests, Pact Hero, Dominion Hero and Conevant Hero for the 3 Alliance zones, and Tamriel Hero for doing all 3 zones' main quests.
So it's not a bug, it's not broken, you do not gain the actual title to display, sorry.
Under your "Achievement" section, you can always see what titles, dyes, cosmetics or other things are associated with an achievement. So if there is none listed under the achievement, you don't get anything other than the achievement points (that don't serve any function other than bragging rights).
"So it's not a bug, it's not broken, you do not gain the actual title to display, sorry."
Okay, thanks for the reply. When I searched, I found a couple threads about broken achievements related to this quest line, so wasn't sure if the title display may have been broken. It was cool that upon completion, all the characters you speak to refer to you by the title "King's arrow". Kind of a bummer, but oh well.