As a few have alluded, are you sure it’s O31 curves? Lionel hasn’t used O31 or O27 in starter set in years. Turn the curved track over, the curve/diameter is encoded in the plastic. If, indeed, it is O31, I’d almost suspect someone switched the track. You state you bought it, but is unclear whether you bought it from a dealer or an individual, whether it was/is a new set.
Steve
