Are you sure what the SBA paid was the PPP interest? Or, was it Small Business Debt Relief payments?

"Established by the CARES Act and revised by the Economic Aid Act, the SBA is authorized to automatically pay 6 months of principal and interest, and any associated fees that borrowers owe for all 7(a), 504, and Microloans (excluding PPP loans and EIDL loans) up through September 27, 2020 even if not fully disbursed.

The borrower did not need to apply for this assistance.

https://www.sba.gov/funding-programs/loans/coronavirus-relief-options/sba-debt-relief"

There also was EIDL loan repayment and Bridge loan repayment:

https://gpwcpas.com/grant-credit-loan-and-other-relief-comparison-chart/

I've seen PPP forgiveness, but not SBA payments for that interest. I can keep looking, though.