We believe that the UI terminology used on the Question Bank Question History page may be obscuring the actual behaviour and leading to incorrect interpretation of what is happening.

At present, with the versioning of questions, the main list of questions uses the "Edit > Edit Question" menu / sub-item form to initiate the editing of the latest version of the question.

Within the Question History page, where all previous versions of the question are listed, this same terminology is used. 

This however obscures the fact that:

1) editing question-versions is effectively immutable, and consequently

2) the historic version of a question that version is not amended, a new version of the question is instead created. 

3) It is also noted that the meta-information about the question in this case does make it difficult to know that that the question-version being "edited" is not the latest one, as only the Version number (e.g. Version 1) is displayed, not "Version 1 of 17", which would provide additional information to the user about exactly what it is they are changing

For instance editing V1 of a question that has 5 versions, creates V6, which effectively reverts all of the changes made in versions 2 through 5.

Whilst there may be some benefit to this "revert to version sort of action", this would seem to not be the normal thought that occurs to a non-technical user. 

A user looking to correct an earlier version of a question (an assuming the question is not set to "Always Latest" in the quiz, and there are say 3 versions) would have to:

1. Edit the affected historic version (v1)
2. Save the changes, creating V4
3. Identify the quiz that was set to ask v1 of the question and explictly update this quiz to ask V4 of the question.

However all quizzes that were using the "latest" version of the question are now asking "v4" of the question and this may not be the desired change to make.

(Context follows)

This was discovered our use of the Accessibilty + Toolkit, which as one of the remediations for an issue found in an "old" version of a question, the tool took the user directly to that version's edit page (e.g v1 above) and user hitting save effectively discarded the "latest" version, which they had not seen to correct. This behaviour (we've been informed) is changed in terms of the detection process so in the future wouldn't be detected unless the question-version is actually used in a quiz, but all of the issues could still be caused manually via the Question Bank UI.