I recently unlocked the "Deadeye" Title and equipped it so that it would no longer blink. When I tried to re-equip the "Chosen" Legacy Title I was unable. I am able to equip other Legacy Titles, such as "Warden", "MMXX", and "Chronicler". One thing that I do notice is that all of the triumphs associated with the "Chosen" Legacy Title are greyed out in the upper left corner, while the triumphs associated with the other Legacy Titles have the gold in the upper left corner. Also, while I am prompted to equip the "Chosen" Legacy Title in the "Chosen" menu, there is no prompt along the bottom of the screen to equip it from the main Title menu, like there is on the other Legacy Titles. I've seen other help articles that mentioned this issue in the past, I really hope that it can be fixed some time soon.