When analyzing the answer's distribution of a test report, you may find that there is one glitch as the report skipped Question 5, as the actual results for the first question moved to the next question.
In the image above, the Q5 was originally created with an extra sentence and Q6 was the updated one.
This is because when a test question is updated, both versions of the question (old and new) are tracked in the test report.
Once that sentence was removed, a new version of the question was created, and this is why the new version showed up as question 6 in the report.
In order to avoid this issue, you need to make sure to deactivate the test first before do any changes. It would be better if you could deactivate the course and avoid the peak time where most users will log in.