There is no direct translation for "king size" in German.
The term doesn’t exist in German, and when you order it, they try to do as near as possible.
German beds for two adults are customarily separate mattresses, and - especially in hotels - separately moveable, to allow separation as needed.
The same applies for the other US bed size terms - be it queen, twin, or whatever. There is no one-to-one equivalent. Bedsizes do not follow an international standard.
