While typing this up I found a thread from 2013 that points this out, and a post from Koichi that he does intend to add the reading as an answer. While no longer an outright wrong answer, it shakes the text box without giving any hint.
Isn’t ちかぢか listed as the main reading?
It is (if readings listed first count as main), which is why I doubted inputting ちかじか, thinking ちかぢか was more correct. When that wasn’t accepted, I doubted it wholesale and just input an outright wrong answer (ちかちか).
It has the reading listed, yes, just like website lists alternative readings to kanji but will still shake the answer if you try to type in ひと when you’re reviewing 人 as a kanji, for example. A pop-up will then also tell you it’s looking for the onyomi reading. That is what happened here. The answer was shaken, except no hint popped up. Maybe hitting Enter again would have accepted it? I have never tried repeating an input after it was shaken, but really it should accept it on the first go.
Shaking without a message is often the result of some kind of error in that moment, not something with the core functionality of the site. This is the main reading taught in the lessons, so I think we’d be getting a lot of messages if it was never accepted.
Do you have other tabs with WaniKani open or any scripts installed?
Nope. No other tabs, no scripts.
Is there no possibility that the reading was added improperly? Added as a main reading in spite of being an addition (going off of that old thread), and added in a way that does not make the system recognise it as a full-on correct answer?
I recently found that the answer box would shake if I put a space in after the word.
I haven’t seen this word in a while, but I know I answered with ちかぢか without any issues.
This is actually most likely what happened. I’m more likely to believe human error than the site erring, if I am perfectly honest. I’m on the tired side today so all the more reason to believe this.
FWIW I had this vocab in lessons a few days ago, so I’ve been seeing it several times now. When I input as “chikadika”, it works fine for me, too.
You can read it as きんきん?!? It’s still one of my leeches and I didn’t even know that… (the meaning of course at issue)