Federal Family Education Loans (FFEL) are not subject to the normal credit report exclusion provisions of FCRA 605(a) until they are repaid.
The fact that everything in your current credit report is clean does not mean that the loan has been repaid.
If the federal loan has not be paid, then they can report delinquencies until it has been paid.
After you pay, the normal 7 years plus 180 days exclusion period from date of initial delinquency, as set under the FCRA for normal collections, will apply.
If the debt is legit, I would pay the loan, either in full or by way of offering a settlement for less.
However, since federal student loans are also exempt from state SOL for bringing civil action seeking a judgment for the entire debt, a settlement for less may be more difficult.
You can always offer......