There were three ribs for each wing that are smaller than the other ribs, these smaller ribs should be at the wing center for sheeting.
see if that is the case and you will not be surprised with six smaller ribs for the other wing.
another issue to check is if all the rib opening for the LE are even and on the same line.
if you used the right type of ribs - 3 small at the center and still have them too big maybe to sand them off a little bit where they meet the LE and sand of the sheeting too.
another idea is to add an angled piece of balsa from the inside so when sanding you will not create a hole.