Looks like the JLPT N5 deck has two of the same cards おべんとう. When I try to learn the card for the second time, I just got stuck, nothing happens when I press Enter, so I can’t move it to the reviews queue.
In the Chrome console I see this:
https://api.kitsun.io/general/lessons/correct?cardId=5b4d0d9ce3b20c73aaf7bd86 Failed to load resource: the server responded with a status of 500 (Internal Server Error) 16.181e047a4c184e514d40.js:1 Error: Request failed with status code 500 at FtD3.e.exports (vendor.b804d8b41650a662328c.js:34) at e.exports (vendor.b804d8b41650a662328c.js:1) at XMLHttpRequest.p.(anonymous function) (https://kitsun.io/static/js/vendor.b804d8b41650a662328c.js:11:32131)
And the response is
{"success":false,"message":"Could not save progress, already completed the lesson!"}