Azure DevOps Create Project Flow - Unable to Add Admins to Project

[JayAdmin_16]

Hello! I'm still quite new to ServiceNow and hoping someone a bit more seasoned in this space can help me. 

The business requirement we have is to build a flow in ServiceNow to Create a project in Azure DevOps. The Action to creation the project works as expected - but adding administrators to the project does not. The Variable Type to add an administrator on this catalog item is in a List Collector Format (which is a requirement), as shown below: 

These are the steps in the flow I have currently: 
1. Get Catalog Variables
2. Look Up User Records

3. For Each item in Items Look Up Records > User Records
4. And finally, our custom action "Add User to Project" (which is confirmed to be working on another form). 

Any advice and gentle guidance would be greatly appreciated,  

[Mark Manders]

What is the result you get? What is the difference between this one and the working one? Where are the limitations? Does Azure only allow one, or what is happening? Do you have any logs?