Not sure if it's the same as pc, but pc is a little weird at first and maybe PS4 is the same. On pc when you go down the list the player's name is highlighted and a popup happens on the right side that says,
"Use this ghost" with a checkmark. Intuitively you click on the players name and think you get the ghost right
? Nope
On pc, if you click on the left where the highlighted part is, it takes you to the players Steam profile, even though on the right side of the screen it says
"use this ghost". To use the ghost you have to move your cursor over to the right side of the player line to where the pop up is that says,
"use this ghost" and click there. It confused me to no end for a few minutes at first
If yours is the same, see if you can use the pad to move to the right once you are on the person's name and then hit "x".