This is perhaps more of a UX feedback item rather than an actual bug but since it involves payments rather than the WaniKani app itself perhaps it belongs here. I found it really confusing to update my payment information on an active (annual) subscription. I recently got a new card and wanted to update my info on WaniKani.
I found this button:
But when I clicked on it and fill out my details I only saw a “cancel” button, nowehre to confirm my input.
Eventually I figured I could update my card under the “Billing” tab instead, but I was stuck on this confusing field for some time.