Pick Many showing as incorrect on review

Hi all,

I am a bit stumped on something and am hoping you can help me out. I am developing an eLearning course and have included a pick many question as part of the assessment. The user has to select three out of five images. However, a problem that has come up in UAT testing is that even though the user selects the right answers and gets the 'correct' feedback, and the results slide reflects the fact that they answered the question correctly, at the end of the assessment when they go to review, the pick many slide shows as incorrect, even though they answered it correctly. Does anyone know what might be causing this to happen? Any help would be greatly appreciated.