Links, audio and web rendering
What you might see
Tapping a cross-reference ("see also", a kanji page like 箱) lands on a 404 or a page that won't open; read-aloud/voice playback does nothing; no Japanese voice at all on your device; or (Firefox on the web app) the page "vibrates" so nothing is clickable.
What's happening
A cluster of navigation and audio defects is tracked together in the issue below: broken deep links, voice playback failures, devices whose system offers no Japanese text-to-speech voice (seen on some Chinese Android ROMs — the app needs a fallback there), and a Firefox-specific layout thrash on the web build.
What to do
Report the exact entry you tapped from (a screenshot of the page you were on pins the broken link) via in-app feedback. For missing Japanese voice: installing a Japanese TTS voice in your system settings usually restores read-aloud while the in-app fallback is pending.