wvd-management-ux | Cannot bind argument to parameter 'ObjectId' because it is null

I tried to deploy the wvd-management-ux template many times, all with the same error: Automationaccounts/job failed code: conflict
going to automation job that failed the actual error is: "Cannot bind argument to parameter 'ObjectId' because it is null"

I am using a Global Admin & Subscription Owner account without MFA.
I have only the two Windows Virtual Desktop enterprise apps.
I tried to run the automation job that failed manually, I have the error:
Cannot bind argument to parameter 'ObjectId' because it is null. (Cannot bind argument to parameter 'ObjectId' because it is null.)
I deleted everything and run the template again. Same error.

my difference from others is that I have a cross-tenant deployment of WVD. My Azure AD with the Synchronized Users and Licenses is on one Tenant but my Azure Subscription is on an other Tenant. I successfully deployed Windows Virtual Desktop by using a user that is Global Admin at the "users" tenant and subscription owner at the "resources" tenant. This account does not have MFA.

with the same account i am trying to deploy the wvd-management-ux template.

more info:
at the "users" tenant I see that an ap registration is created successful with a random name like: wvdSaaSwvdgui02784f8ed833f0497cb1c
and at the "resources" tenant I see all the resources (app service, automation account)

please advice

Start with the wvd-management-ux template and the failed Automation job, using the reported cross-tenant deployment between the users and resources tenants as the reproduction setup. Trace where the null ObjectId is supplied and verify the template deploys successfully without the Automation job conflict or null-parameter error.

Written by the indexing model from the issue text.