Kanji window isn't updated

[ze96]

At least two times in reviews, I've come across the behaviour that the Kanji window doesn't update, i.e. it's keeping the text from the previous Kanji. If not paying attention properly (I wasn't vigilant enough), you'll get marked with a wrong answer. The Kanji window updated first when the answer was confirmed, i.e. when it was already too late...

Both of my times happened on vocabs and during lesson review if that's any help.

I'm using a Samsung S7.