Give right anwer but show incorrect

Question

I have gave the correct answer in a multiple selection quiz, but it shows incorrect answer, iǘe selected all the posible answers and it keeps showing wrong. Can't continue with quiz!

Answer 1

Given that you've chosen not to mention which question it is I'm assuming that you're neither looking for help, nor trying to report a bug. So I'm a bit at a loss as to what you want.
¯\_(ツ)_/¯

Answer 2

If you think this is bug send report to support. Also screenshots will help tham solve problem if there is any.