Nuka World Star Core help

I have all the star cores and am putting them all in, however i have 4 leftover. I counted all slots and have gone over the mainframe for an hour now, I have counted 20 times and only count 31 slots. Every time I count the slots shown there is only 31, am I missing something? I have all star cores, the mainframe hasn't changed, but there's nowhere to put these star cores so I can't access the power armor.