What went wrong?
When trying to re-map the [B] button on the controller it will close the menu, which is technically the default secondary function of the [B] button, but it shouldn’t close the menu when trying to assign it to another function (such as an ability slot). I’m using the Xbox Series controller.
In the video below I try to assign the [B] button to my 5th ability slot, but it closes the menu before I can choose to replace it.
Video