What is wrong in "they are not humans"? I think it is more suitable translation. They are not humans but elves.
So, lide means folk in one question and then folk is not an acceptable answer in a few questions later?
I believe you are referring to a sentence that talks about "good folk". You can use it as a translation for people there. But in a sentence where we speak about something not being human, folk does not really make sense in English.
it is like. "It is not a man-human" vs. "he is a good chap". You would not say "it is not a chap" meaning that the object-creature is a non human.
I typed the exact thing and it wasn't accepted. I think there's still a bug?
Yes, you can report to Duolingo using the official bugreport form. But it is good to have some evidence, like screenshots. But in my opinion they have many reports already.
Unfortunately, you chose wrong thing to report, you did not use "My answer should be accepted." but all other reasons (wrong sentence, wrong solution, wrong audio). Please do not do that, I had to delete those reports.
The option for "My answer should be accepted" was not even there when I tried reporting! It was too bad that you had to delete the reports but it was one of the ways to get yall to notice it.
It is a bad way to notice, do not do that. Normally I would just delete them and swear. This way I knew it was you so I swore a bit less...
We do not really know what we should do with such nonsense reports. It is just a nuisance to delete these but they don't tell us anything useful. Just that someone was unsatisfied in some mysterious way.