mmmhhh, could it be that the option#55 must be in the right order to work ?!
I had it like you before and it didn't work so I've put in the right order and then it was OK.
To make sure I've changed it back and it still was working but then I've deleted the end-system in the NAC and it wasn't working once again.
So back to the right order and now it shows XBOX ONE again.
...not sure but I'll leave it like that.
dhcpoption55="1,3,6,15,31,33,43,44,46,47,121,249,252"