on appeal, see Coventry Br. at 45-55; Griswold Br. at 26-28. In a brief footnote in its reply brief, Coventry acknowledges that stale law may be applicable. See Coventry Reply at 24 n. 8. That belated and undeveloped argument is insufficient to raise a choice-of-law issue on appeal. See Neely v. Club Med Mgmt. Servs., Inc., 63 F.3d 166, 180 (3d Cir.1995) (enbanc) (observing that "choice of law issues may be waived”). Because we are satisfied that the Supreme Court's decision in Arthur Andersen did not overrule Third Circuit decisions consistent with relevant state law contract principles, we may rely on our prior decisions so long as they do not conflict with these Georgia and Pennsylvania state law principles. See Kramer v. Toyota Motor Corp., 705 F.3d 1122, 1130 n. 5 (9th Cir.2013) (<HOLDING>). 7 . The other Appellants—Coventry Group,
holding that prearthur andersen federal decisions consistent with relevant state contract principles remain good law holding that state courts in construing and interpreting state law are not bound by the decisions of federal courts holding that the plaintiffs state law claims are preempted by federal law holding that state court with jurisdiction over  301 claim should have applied federal labor law rather than state contract law recognizing that decisions of lower federal courts interpreting federal law are not binding on state courts