Bugs are best reported to hello@wanikani.com
Also, if it is one of the apps, those are all third-party and unofficial. Make sure that the problem persists in the regular browser version before reporting it. Otherwise go to the thread here on the forum pertaining to the particular app that you’re using.
Is this the app called just “WaniKani” on Android?
And if it’s the one I mentioned, that’s not being supported by the creator anymore…
That makes sense. WK does seem to have been making back-end changes, so unsupported apps like this might be dying. Especially if it takes API 1, I would guess.
Also @bgdn tsurukame is often used by iOS users, and Flaming Durtles is very popular for Android users. ^^
And: welcome to the Community! 
Makes sense. I caught this bug in WK app. Tested it via browser, everything works as it should. Many thanks 
Thought you were writing about the vocab meaning “bug”. 虫
Haha I thought so too 
Happy Birthday by the way!