XF 1.5 why isnt username css working [screenshots]

[Senpai]

what is happening her im soo confused why is my user group CSS not working i tried looking for every tutorial but nothing seems to work
can someone tell me what am i doing wrong i tried putting it primary and that didnt work too i tried nearly everything at this point what can i do

user group in admincp:

and screenshot on member that has the group

and this screenshot is settings for the member

 

[Mike]

Try rebuilding the user cache via the control panel. Does that resolve it? If so, there's probably an add-on that has interfered with display group calculation.