Translation:My apologies! I am late!
"Sorry for being late" should have been accepted, right ? Or am I not?
Duolingo expects separate statements instead of combining them together to form a single English sentence. Otherwise, the interpretation of that English sentence would suggest that the readers treat it as a different wording, thus a different wording.
Why "sorry for being late" is wrong. Again???!!!! Can't you fix bloody AI??
This translation is good because it matches an English speaker better, but a more direct translation of "wo3 chi2 dao4 le" would be "I arrived late".
IMHO this should also be accepted.