"Pick one" freeform quiz allowing multiple selections in SL3

I have a few freeform quiz slides with a few objects grouped together into two groups.  The groups are used as the answer options.  After "adding" an image to each group (ungrouping, then regrouping with the new image, then renaming the new group back to the previous group name), I click one answer and the Selected state activates correctly.  When I select the other answer, the Selected state activates on the new answer, but the first answer group still stays selected.  When I submit the answer, even if the most recent selection was the correct answer, I am told that I am incorrect.  This is in preview mode, I didn't try publishing the project to see if it acted the same way in a browser.  I found a workaround where I create a new Freeform Pick One slide and copy the two groups from the old slide and configure the answers on the Form View tab, it works as expected.  Possible new bug with update 12?  This is a project that was created in an older program version and this is the first time opening it in update 12.  Answers acted as expected before I made changes, I suspect it may have something to do with grouping/ungrouping and reusing the group names but I haven't tested.