Yes @justinburch, actually the site setting to match existing contacts is not working but yeah pretty much I am facing the issue you described, other site settings are as shown in the screenshot below



I am very confused about the portal login, We use to use Local Login were when ever a contact is created in CRM it would make it a portal contact and set some default password for it using the OOB actions.
But since the local login is deprecating, I am not sure how to convert the functionality we were getting from the local login in some other Login method.
All I need is my contacts should see the cases related to their accounts, but with Azure AD it creates a new contact and that new contact is not linked to my account, I am confused.
Can you suggest some login method which will help me achieve the functionality I described above.
Thanks You for all the help !