Accrued market discount on US T-Bill, Form 1099-B?

Received Form 1099B with some accrued market discount for a T-Bill transaction, is this to be reported as interest? All other T-bill transactions are reported on the 1099-INT form as "interest from US government securities or Treasury obligations" but for some reason, this single T-bill purchase is included here.

 

Would appreciate any guidance on how to treat this?