When multiple users add child incidents in the Child Incidents related list, the records added by the first user/s are removed from the parent record when the second/last user clicks on SaveSummaryThe issue is reproducible on OOB instances. The issue occurs if both users have the list collector open at the same time. Steps to Reproduce: 1. Hop on to an instance that has major incident application installed2. Impersonate an itil user3. Open a second browser/incognito window and impersonate a different itil user4. Open/create a major incident5. Open the same major incident by both the users in their respective tabs/browsers6. Click on the Child incident related list and Click Edit**Note: Both users must have the list collector open at the same time.7. As User 1 add a few incidents to the Child incident list and click save8. The incident records are added as expected9. As User 2 add a few different incident records and click save Expected: The child incident list should contain the incident records added by both users Actual: The incident records added by User 2 are added to the list but the incidents added by User 1 are all removed from the list. Product Development team have confirmed that this is expected platform behaviour. i.e.When a user selected the records to add as child incidents and clicks on save, it will add the selected records and remove the one's that were not present in the selected list. Hence the child incidents added by user 1 will be overridden by user 2.