Agree. Really maddening. And if you're working with hearts, and you had only one left, you have to repeat the whole lesson. I really get upset when the course plays tricks like this at the end of a lesson!
This example of Duo's ridiculous pettiness came up immediately after one of his annoying messages saying ".......,.you can do it" Maybe I can, but I'm not sure I can put up with his nonsensical rejections much longer!