But I am able to access the metaDataPolicy if I give the Collection Admin role through purview portal. How is it any different from giving the Collection Admin role through Powershell? You can see in the 3rd screenshot I shared that my service principal "workx1prsp" does get the Collection admin role in the root directory and that is the only role I need to access the meta data policy. The Rest API document states that too

If you're using the API, the service principal, user, or group that executes the API should have a Collection Admin role assigned in Azure Purview to execute this API successfully.

And it works if I give the role from inside the purview portal manually but fails when I use powershell command.

Using Add-AzPurviewAccountRootCollectionAdmin to grant the collection admin role is not the same as granting the role through purview portal? If yes, why?
Why does it still reflect as collection admin in purview?

EDIT: I have also tried giving the RootCollectionAdmin role through the rest Api by sending "POST" request on https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.Purview/accounts/{accountName}/addRootCollectionAdmin?api-version=2021-07-01 and it gives the same error. The role reflects as granted in the purview portal but I still cannot access the meta data policy

Any update here?

Thank you for the response.
I don't have a support plan, is there anything that can be done? The issue is still present. I am only able to access the meta data policy if I give the Collection Admin role from Purview portal. If I use any other method to grant the Collection Admin role, Powershell, AzureCli or Rest APi, I get the "Unauthorized, Not authorized to access account error|

My service principal in ADD

Granting Purview Root Collection Admin role

Purview Roles

Generating access token

Unauthorized to access collection policy

I am pretty sure I have passed the authorization correctly, because the same request works if I manually assign the role through Purview Portal. Anyways, here is the screen shot of the error if I provide authorization through "Authorization" tab.

The Add-AzPurviewAccountRootCollectionAdmin command works and shows me that the role is assigned in my purview portal, but I still don't get the permissions to do anything I could do with that role. I can't add collections, can't get meta data policy, etc.

So I've made a video of the error. I've used to the REST API method to grant RootCollectionAdmin role. The same error happens with Powershell and Azure cli, I just used to REST API method because its easier to record and edit that way.

https://youtu.be/Uw6KdBcrk-M

Thank you for the answers @PRADEEPCHEEKATLA-MSFT

Just wondering if there is something I could do to permanently fix the transient/temporary issues because I'm getting it more often now. Any idea on what might be causing it? Right now I'm just using a while loop which just redeploys my purview account if the previous provisionState goes to "Failed".