Incidents are getting assigned to the group members which are not belong to the respective group.<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } IssueIncidents are getting assigned to the group members which are not belong to the respective group. Steps to Reproduce: 1.Navigate to All → System Policy → Rules → Assignment Lookup Rules. 2.Create a custom Assignment Lookup Rule with the following values: Category: Inquiry / HelpSubcategory: EmailAssignment Group: NetworkOrder: 0 3.Navigate to All → System Policy → Rules → Data Lookup Definitions. 4.Open the existing "Assignment lookup" record with source table "Incident". 5.In the Setter Field Definition related list: Open the assignment_group record.Set Always replace = true. 6.Create a new incident record. 7.Set: Category: Inquiry / HelpSubcategory: Email 8.Select an Assignment Group other than "Network" and choose an Assigned to user from that group. 9.Save the incident. 10.Observe that the Assignment Group is automatically changed to "Network". Release All Releases Cause This issue is caused by a custom Data Lookup Definition that updates the assignment_group field after the incident is submitted. In the Setter Field Definitions, the assignment_group field is configured with Always replace = true.When this option is enabled, the data lookup rule overwrites any existing value in the field, even if the assignment group was manually populated during incident creation. As a result, the assignment group is forcibly reset based on the lookup rule, which can cause incidents to be assigned to users who are not members of the final assignment group. For more information, refer to ServiceNow documentation: https://www.servicenow.com/docs/bundle/zurich-platform-administration/page/administer/field-administration/reference/r_CreateCustomDataLookups.html Resolution 1.Navigate to All → System Policy → Rules → Data Lookup Definitions. 2.Open the existing "Assignment lookup" record with source table "Incident" 3.In the Setter Field Definition related list: Open the assignment_group record.Set Always replace = false. Result The data lookup will only populate the assignment group when the field is empty and will no longer overwrite manually selected values.