At the moment it's not possible to create Supervisory Nodes and Requisition Groups, because there's a circular validation that enforces the presence of those resources. Supervisory Nodes require Requisition Group and Requisition Groups require Supervisory Node. As a result of this, neither resource cannot be created, when setting up the system from scratch.
Validation to enforce requisition groups while creating a supervisory node was introduced in - this likely shouldn't be done.
It's possible to create Supervisory Node without providing Requisition Group
Requisition Groups still require Supervisory Node when creating them
After those fixes the bug from must not come back
Updating Supervisory Nodes and Requisition Groups works properly (including changing the supervisory node in requisition group)