Behaviours setRequired method on User Picker field can prevent the user selection drop down clearing

If you have a behaviour that sets a User picker to required after a change is made to the field (i.e. a field server-side script) the drop-down section that shows a user name which matches the text you enter never gets removed from view when you select a user.

The action of setting required after triggering the user interaction event on the field seems to trigger another user action event which then causes the suggested user dropdown to re-appear.

See video here BehavioursBug.mp4

Steps to reproduce:

1. Create a User Picker field (Jira field)
2. Add a behaviour to that field. Like this:

   String destinationStepName = getDestinationStepName();
   String statusName;
   
   def field = getFieldById(getFieldChanged())
   
   if (destinationStepName != null) {
       statusName = destinationStepName;
   } else {
       statusName = underlyingIssue.getStatus().getName();
   }
   
   def statusList = ["Done", "In Progess"]
   
   if(statusList.contains(statusName)){
       
       def  value = field.getValue()
       
       field.setRequired(true)
   
    if(! value){
       
       log.error("no value selected")
       
    }else{
       
        log.error("A value has been selected")  
    }
       
   }else{
      field.setRequired(false)
   }
   

3. set a transition screen on the Done transition
4. Attempt to select a user with the behaviour active and the dropdown selection box should never disappear.

Workaround is to set required in the initialiser instead of the server side script on the field