I haven’t used Wanikani in a long time and lots of reviews piled up, about 700. I have pushed a bunch of items to enlightened the last time I used it.
In the last week I did some reviews and I answered some of the enlightened items incorrectly. They showed up again in the next review I did, I could answer them and they burned. I this intended?
If you answer only one half of them and then quit the review session halfway, this will happen. If you want to avoid this, you can click on the clock symbol towards the bottom of the window: It will let you wrap up your session by presenting you the second halves of the ongoing items.
If that was not the issue, then maybe it’s a bug? (How did you do your reviews anyway? Did you use an app, or the website?)
For Android, an app called Flaming Durtles seems to be popular, but I cannot say anything about it, sorry… (but if you search around the forums, you should find plenty of information)