Translation:Kateřina and he are honest with each other.
As for this particular sentence, the word order seems forced in the translation: I think it sound more "normal" to put the pronoun in first position and the proper name second. "He and Kateřina..."
I'm not sure that I agree with that stack exchange answer. And from a quick google it doesn't seem like that importance rule is very widely known.
Yes, take it from a native speaker that we would say "He and John" way before we would say "John and he". The stackexchange answer is incorrect
All the listening exercises have started bugging. I am getting word suggestions for the answer (which I didn't use to) and despite typing (or assembling from the word suggestions) the correct answer, I get an error
There is no way we can help, you have to complain to Duolingo, not to individual sentences. Prepare some good evidence like screenshots.
Figured, but couldn't find a way to report the bug. It's not an option in the "report" section (these only speak to the translation). Thanks anyway!