not every quality stainless is non magnetic. ever see those magnet bars for hanging your stainless kitchen gear...?
300 series ss is non magnetic. 303, 304, 316 etc.
400 series is. 410, 420, 440 etc. These are more of a tooling steel that gets hardened.
I would suspect the magnetic one is just plated steel. There is a definite color (hue) difference between them.
Clean well and look at backside visual differences in color. Not just surface finishes.
Mike