I used mine (PA) account, but I read it doesn't matter which account to use (Sponsor or PA). It just cant be linked to both account I thinkThanks for encouraging. Did you link with PA gckey or Sponsor's gckey?
I tried with mine I.e. sponsor gckey but unable to link as we don't have UCI for PA.
Did you put UCI number in application? If yes, maybe it would work. Otherwise there's option to use PA's First and Last name + Date of Birth.