I was doing my extra study this morning and noticed some strange behavior both for the Recent Lessons and for the Recent Mistakes.
This image shows that I have 40 recent lessons and 25 recent mistakes.
And this is the results screen I am getting after completing both the Recent Lessons and Recent Mistakes:
I think the Recent Mistakes did have all 25 recent mistakes and just the results screen is off, but the Recent Lessons only gave me the last 10 lessons I did and the results screen is the same. I also did both of them several times and even if I get those two incorrect ones correct, they still show as incorrect in the results screen.