"Kdy odešly?" should not say that I have typo since it is impossible to know from the audio if it was said with "i" or "y" at the end.
I know the "i" answer would be more common, but there is plenty of cases when only females had left.
"Kdy odešly" is version 109 of 163 possibilities. Duo sometimes confuses itself, specially when it comes to a difference in one letter.
It is impossible for anyone to recognize the two from the spoken form of a single sentence. But it is better to have a typo message for some students than to block the whole audio exercise.
I was just surprised I could not report with "My answer should be also accepted" or something like that, not sure if Duolingo allows multiple answers for hearing excercise but it should for Czech.
You can try to ask the Duolingo developers (we are just langauge contributors), but they have many more important problems to deal with. It would be very hard to implement.