Originally Posted by
jrl767
it’s a DL award … KL flight number, with a notation that it’s operated by German Airways
the “Seat Selection” link on the app says “Oh no! We’re sorry but seat map for this flight is not available. Contact German Airways GmbH …”
the fact that KL wouldn’t sell BKK-AMS-FRA on these flights should have been a clue (but along the same lines, I’m a bit surprised that the 13-hr overnight connection didn’t appear)
In addition to what FlyerCo has explained, the seat selection for the GE-operated flight on behalf of KLM should work if you log in to manage your trip via KLM website.
By the way, if it's not a rainy day, the views are nice on the AMS-FRA flight, as most of the flight is at a low altitude