This seems like another puzzle where the opponent doesnt act rationally.

Instead of rxd7 wich obviously leads to a forced mate in 3, kxd7 gives the black king at least a glimmer of hope and probably not a mate in 5

As the gentleman in post #63 demonstrated, Kxd7 is still mate in 5.

Yes indeed, but by capturing with the king you at least give the opponent a chance to make a mistake. Im merely saying that in these puzzles where we obviously are not  ment to resign,  we might as well play for our biggest chance of survival. And when this puzzle has 4 possible ways to mate in 5, I find it wrong that the only "correct" solution is the one with the most obvious forced mate.