Recently noticed, whilst trying to diagnose another issue, that we are now unable to move/reorder items within a job.  

Attempting to move/reorder items in the build or post-build  section results in the browser scrolling upwards with no ability to move item.  Tried on multiple browsers and computers.

Steps to reproduce:

1. Create a freestyle project
2. Add multiple build steps
3. Apply changes
4. Reload the page (it only affects steps that were present when the page was loaded)
5. Try to drag/drop build steps with the handle in the top left to change their order

Expected result: It works

Actual result: It doesn't

Notes: The "placeholder" rectangle appears further up the page.