Cornerstones repeatable in 6 days but expires in 30 min

Honestly this doesn’t make any sense. I bought multiple players used my reward corner stone and paid fifa points for another, was gonna do 1 more but it says I can’t repeat for 6 days and it expires in 30 min. EA wtf is that, if it’s under the 7 day rule for repeating then why can’t I still buy the evo? Just ruined hours I spent planning a team and half my coins are gone, and now I have 4 players on 2 chem, thanks guys