Originally Posted by
FabCW
If it’s operated by Air France, don’t check the Delta app and website. Instead, check your itinerary on the AF app or website. You can even use your DL booking number.
This is the correct approach. I've had issues using my DL PNR on AF or KL sites, but a simple call to DL gets me the operating carrier's PNR. Regardless, if you want accurate info, you always gotta go to the operating carrier.