Description
When previewing answers (or as an instructor showing correct answers), the scaffold part headings are still colored and opened based on the correctness of the inputted answer, so students can get info about if an answer is correct or not without using any submits by previewing their answers.
To see this, test a scaffold problem as a student, enter in the correct answer to the first part, and click preview answer. The scaffold will turn green to state they got it correct, and the next part will open up. In essence a student could work though the whole scaffold problem only using the preview answer button, then use a single submit at the end when they get it correct.
This might not be fully a pg bug, could be with its interaction with webwork2.