def group = com.atlassian.jira.component.ComponentAccessor.getGroupManager().getGroup("group-name") // Get the group you want to set on your custom field
issue.customFields."Group Picker CF".value = [group] // Use your actual custom field name or id
Make sure to change .getGroup(“group-name”) to the actual name of the group you want to set as a default
Change “Group Picker CF” to the actual name of your Group Picker custom field.
Can you send a screenshot of incoming sync rules on the destination side? Also a screenshot of the group that you are trying to set from the Groups screen.
Exalate has problems performing an issue update in this Jira. Details: java.lang.String cannot be cast to java.util.Collection
Error Stack Trace
com.exalate.api.exception.IssueTrackerException: Exalate has problems performing an issue update in this Jira. Details: java.lang.String cannot be cast to java.util.Collection at com.exalate.node.compatibility.CompatibilityService.updateIssue(CompatibilityService.java:548) at com.exalate.node.hubobject.v1_4.NodeHubIssueHelper.updateIssueWith(NodeHubIssueHelper.java:686) at