Identify a freeze/"stuck" issue when Next is submitted

This job is to identify the cause of a freeze issue we have - we have an online exam, and when a user clicks on "Next" sometimes the question freezes/gets stuck and won't go on to the next question. The issue is most likely a Javascript/Jquery functions call issue ([login to view URL] are many functions called at the same time) - we are certain it is not database related. You need to IDENTIFY the issue, not FIX it - but you will need to provide instructions for us to fix the issue - payment will only be made if the issue is fixed by the instructions you provide.