Set form value in behavior initialiser script but Fields script unable to get that value

[Marcus Yu]

I have a behaviour that uses an Initialiser script to set a custom user picker field to the currently logged in user and this works without issue.

import com.atlassian.jira.component.ComponentAccessor;

if (getActionName() != "Create") {
    return;
}

def userField = getFieldByName("Target User");
def currentUserName = ComponentAccessor.jiraAuthenticationContext.loggedInUser.name;
userField.setFormValue(currentUserName);

 But I also have a server-side script on that same "Target User" field in the same behaviour that checks the value of the "Target User" field and if that user is the same as the currently logged in user a "Requester Agreement" custom checkbox field would be visible and required. If they are not the same user then the "Requester Agreement" custom checkbox field would be hidden and not required.

The idea is that initial, when the form is initialized the "Target User" is set to the same as the currently logged in user and because of this the "Requester Agreement" field is visible and required. But if the user changes the "Target User" field to another user then the "Requester Agreement" field is hidden and not required.

import com.atlassian.jira.component.ComponentAccessor;
import com.atlassian.jira.user.ApplicationUser;

if (getActionName() != "Create") {
    return;
}

def currentUserName = ComponentAccessor.jiraAuthenticationContext.loggedInUser.name;
def targetUserField = getFieldById(getFieldChanged());
def requesterAgreementField = getFieldByName("Requester Agreement");

log.info("Target User: $targetUserField");

if (currentUserName == targetUserField.getValue())
{
    requesterAgreementField.setHidden(false);
    requesterAgreementField.setRequired(true);
}
else
{
    requesterAgreementField.setHidden(true);
    requesterAgreementField.setRequired(false);
    requesterAgreementField.setFormValue(null);
}

But for some reason the "Target User" field has a null or empty string value. The logs show: 

Target User: Form field ID: customfield_10700, value:

I can't figure out why this is... I see the logging lines in script being run at least 2 times when the form loads but rarely the form will load 4 times and on the 4th time the "Target User" field will actually show the expected value.