Cannot create behavior on new element in element form

[ccrowley96]

Describe the bug
Cannot create behavior on new element from behaviors tab.

To Reproduce
Steps to reproduce the behavior:

1. On Elements tab
2. Click on 'Create element'
3. Click on behavior pivot within elements for
4. Click on 'Add behavior'
5. Select 'Create behavior' from callout --> this throws (during element initial creation)

Expected behavior
Action is taken after clicking 'Create behavior in callout'

Screenshots