After you go to Market Permissions under any individual customer and change it, you can't see the properties "ChangedOn" Also "EntityLastChangedOn" updated with the recent values on OData payload.
SAP Cloud for Customer
Reproducing the Issue
1. Go to Individual Customer work center.
2. Update the Marketing Permissions.
3. Observe the latest change on change history.
4. Perform the GET call to check the payload e.g.: https://myxxxx.crm.ondemand.com/sap/c4c/odata/v1/c4codataapi/IndividualCustomerCollection?$filter=CustomerID eq 'CustomerID123'
5. Check for the ChangedOn and EntityLastChngedOn properties.
6. The latest change done on Marketing Permissions will not appear in OData payload as you can see on Market Permission change history.
As Marketing Permission is not part of the customer service there is also no update on EntityLastChangedOn when marketing permissions are done.
This data is not part of the customer object and also not the service so that can't be expected that "ChangedOn" and "EntityLastChngedOn" properties change on OData payload when Marketing Permissions are done.
This is the system behavior.
OData, ChangeOn, EntityLastChangedOn, Market, Permission, Payload, Individual, Customer , KBA , LOD-LE-BP-BP , Business Partner , How To