Training puzzle

lichess.org/training/38554

In this position, I played Qf7+ which leads to a mate in 4 when playing against the computer. However, my solution failed because the expected solution was Rd7 which also leads to mate in 4.

Has anyone looked into that puzzle? Isn't it sad to have a mate in four marked puzzle failed when the solution is also a mate in four. How can a mate in four be a better solution than another mate in four?