How to configure Add Smart action for objects having 1:M relationship?

Summary:

Add client is a UI based smart action on account object.

Account and client having 1:M relationship.

When We hit Add client in layout we have enable client id field and applied CX- picker.

But it is not saving data as expected.

And If we apply cx-picker for Record Name field . It Is creating new record instead of Adding exiting client to the particular account.

Content (please ensure you mask any confidential information):

This is smart action configuration. We have selected source object as Account and Target object as OrganizationDEO_Client_Tgt which is intersection object between account and Client.