Transaction not yet indexed

Am18MdK5CovRjj1UymLmxpNpQH6hmgok5rNipjLcWpVTpSC1jXe9kDmCPMgkC2PeFmGRU5Bg9r3MHGo2CDvZdz1

The transaction signature is valid but not yet indexed by this RPC node, or the transaction failed before inclusion.