Errors in the iOS version
Can't get the application to work optimally,keep getting error even though press on the correct answer. I have tried refreshing,even uninstall and reinstall the application.
In the multiple choice activities, you have to mark all correct answers. Often that means marking two answers at once, and occasionally marking three. If there are two correct answers, it will not give you credit for marking only one.
I'm a Droid myself, but have you tried updating the application? Also, how long has this problem been happening? Possibly it's a bug in some new update that Duo hasn't gotten around to fixing yet.