Add / edit start task won't load when user account present on pool create

[davidkydd]

Describe the bug
During create a new pool workflow, when a start task is added, then a user account, the startTask can no longer be interacted with / edited.

To Reproduce
Steps to reproduce the behavior:

1. Go to Create new pool
2. Click and add a starttask
3. Then add a user account
4. Try to click on startTask and nothing happens, remove startTask and cannot re-add it
5. Remove user account and startTask works as normal

Version (please complete the following information):

• OS: Windows
• Version 0.19.1-stable.216