Hey Peter, so the issue started happening again (without adding any new cards btw). but I have more information about it issue that might help.
So with more investigation, It seems to be showing the previous answer (not random as I thought. This initial false claim was just due to my poor observation skills). second, If the wrong answer appears, If I click the text as to highlight it. It switches to the correct answer. so it does seem like a graphics thing? I'll attach a short video of this being demonstrated. As you can see, the answer displayed for the "Play soccer" card was correct 踢足球. but then the answer is repeated for the next card which was "to want".
Also, It appears that the issue has nothing to do with adding cards. I assume I was projecting a pattern that didn't really exist.
Let me know if this insight helps.