Did you fail to mark the IRA/SEP/SIMPLE box on one of the Forms 1099-R from these traditional IRAs?
If a Form 1099-R provided by the payer does not have the IRA/SEP/SIMPLE box marked, the distribution is not from a traditional IRA and does not go on Form 8606.
Does the amount differ by the amount shown on one of the Forms 1099-R? If so, that's the form to look at.
