Hi Alster friend :)
Sometimes even the slightest difference in ball spin can add or remove quite some yards on a shot like that, with big elevation difference.
My tip is to play that hole on a practice round, and make the shot without spin several times, taking mulligans after each shot.
When you feel you get a pretty consistent result, try the shot again with some backspin, also taking mulligans and then use different amounts of spin to see how it affects the ball path.
Viel gluck Zetze, CYA around!