TR-SRO Party Buff Pain Quota is not working

Well as you can understand from the title I’m not able to use party buff pain option. I’m clicking on the arrow that should be add selected user to the Pain Quota but nothing happens. When I select buff everyone it works but I want to select specific name.

Scroll to the bottom and add their name to the specific buff.

Thanks for the answer but if you check the screenshot below you will see that Pain Quota is selected and when I clicking the add arrow nothing happens.

I’ve found the solution. I’ve supposed the select Immortal Victor instead of Pain Quota.