Japanese listening questions don't accept kanji.
"Type what you hear" type of questions often reject kanji. And unlike translation questions, "report" doesn't contain option "my answer should be accepted" .
If you don't know about Japanese, some words in Japanese can be written in kanji instead of hiragana. But sometimes if I write the entire sentence in hiragana, it gets rejected too even if it's correct. So I need to guess which words should be written in hiragana and which words should be written in kanji.
Of course I could use word bank instead of keyboard, or just turn off listening questions. But that's not really good for language learning. I believe there are a lot of people like me who get frustrated by this. Can we get some technical support?
I totally share your concern and I agree with you that this is an important shortcoming of the Japanese course. It can be aggravating to try to guess when it wants Kanji and when it wants Hiragana, and what particular combination it needs to accept. And the fact that they don't even have a report button is like they're spitting in my face. Isn't it obvious that this would be incredibly frustrating to learners? And they're not even creating an opportunity for people to fix or improve it.
This has been a problem since they introduced these exercises, and it hasn't been addressed or (to my knowledge) even acknowledged by the staff.
I recommend going elsewhere. The people who run Duolingo aren't serious about addressing concerns like this, and as such, it's always going to remain a mediocre learning tool.
I recommend tools such as Delvin Languages and, once you get more advanced, Clozemaster. Jisho is also a good supplemental tool to look things up.
The Duolingo Japanese course has always been crap...it was crap at launch and they've made only piddly progress in the many months since launch, with no sign of addressing any of the deep problems like this one you give an example of. As such, trying to use it to learn is going to be at best frustrating and at worst, a huge waste of time.
I agree, this should be fixed as soon as possible. So far I've been reporting the correct answers as unnatural which is the closest thing you can get to reporting this issue. If they get enough reports about this, they might fix it.