Hyundai P1326 code

To all the kia/hyundai techs out there, my girlfriend has a 2018 Santa Fe with about 140k mi that popped a p1326 code about 2 weeks ago. Went into limp mode out of the blue. Took it to the local dealer to see if they’d cover it under extended warranty because I remember reading up on a TSB for that code on the gdi v6. The vehicle still idled perfectly smooth when I checked it out and scanned the codes.

The stealership is telling her that it requires a full $1500 tear down before hyundai will even consider covering an engine replacement under warranty. Advisor told her that it “had a broken valve” and that’s why it wouldn’t rev above 3k rpm’s. Again, it ran perfectly smooth before it went into the dealer and only had the one code. I’m not a Hyundai tech, but I’ve got 6 ase certifications and that makes absolutely no sense to me. I understand that code will set for main bearing wear, but it sounds to me like they’re trying to get $1500 from her before denying the warranty claim and charging her $8k for an engine replacement. I should add they’ve had it for 2 weeks now with no calls in until today.

Should we take it to another hyundai dealer? Try our luck with marketplace? Or just bite the bullet and pay for a new engine?