Why is that when I search for: https://jisho.org/search/%E3%81%8A%E8%85%B9
【なか】reading is there, but in entry for kanji itself, it is clearly missing: https://jisho.org/search/%E8%85%B9%20%23kanji
I've checked also in Kodansha Kanji Learner’s Dictionary, 2nd Edition (Jack Halpern), but to no avail.
Is is just this specific case, or are there more like that? If so, what is the rule of thumb to deal with that?