Moving forward and backward through a CSW workflow

Summary

Moving forward and backward through a CSW workflow

Content

We have a request , where steps within a workflow are optional :

New Candidate - Mandatory - restricted
Hiring manager review - mandatory
Video interview Optional
testing ( Optional)
Interview / assessment - mandatory
RSOFFER
Vetting - mandatory
Hire - Mandatory

All have relevant status within each step.

Able to move candidates forward through the steps ,and "bypass" optional test . example, move from Hiring manager to Testing ( Optional) missing Video interview  but do not seem to be able to move back from Testing , to Video interview optional as the fields in the "new Step" ,is greyed out and protected , and unable to select.