Azure Powershell script throwing 'Forbidden' - azure

Question

I have a powershell script that is throwing error. I am trying to create an Alert Action Group through powershell. The last line is throwing error.
$TenantId = Get-AzTenant | select Id
Connect-AzAccount -TenantId $TenantId.Id -SubscriptionName $SubscriptionName
$Receiver1 = New-AzActionGroupReceiver -Name $ActionGroupReceiver -EmailReceiver -EmailAddress $EmailAddress
Set-AzActionGroup -Name $ActionGroup -ResourceGroup $Rg -ShortName $ActionGroupShortName -Receiver $Receiver1
I have Owner access to the subscription and can confirm that all of these variables have appropriate values.
The same code worked for a different subscription in the same tenant where I have contributor access. This is probably an access issue however I am not able to figure why I am getting Forbidden even with Owner access.
Edit - Error text
Set-AzActionGroup : Exception type: ErrorResponseException, Message:
Microsoft.Azure.Management.Monitor.Models.ErrorResponseException: Operation returned an invalid status code 'Forbidden'
at Microsoft.Azure.Management.Monitor.ActionGroupsOperations.d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Management.Monitor.ActionGroupsOperationsExtensions.d__1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.Azure.Management.Monitor.ActionGroupsOperationsExtensions.CreateOrUpdate(IActionGroupsOperations
operations, String resourceGroupName, String actionGroupName, ActionGroupResource actionGroup)
at Microsoft.Azure.Commands.Insights.ActionGroups.SetAzureRmActionGroupCommand.ProcessRecordInternal()
at Microsoft.Azure.Commands.Insights.MonitorCmdletBase.ExecuteCmdlet(), Code: Null, Status code:Null, Reason
phrase: Null
At C:\Users\YashTamakuwala\Desktop\live_traffic\Alerts\Alerts\CreateActionGroup.ps1:25 char:1
Set-AzActionGroup -Name $ActionGroup -ResourceGroup $Rg -ShortName $A ...
+ CategoryInfo : CloseError: (:) [Set-AzActionGroup], PSInvalidOperationException
+ FullyQualifiedErrorId : Microsoft.Azure.Commands.Insights.ActionGroups.SetAzureRmActionGroupCommand

Answer 1

I found the problem. I tried performing the same action through portal but couldn't. Got this error.
There were policies in place to prevent such activities. Also, the requests from powershell are tracked in Activity Logs which in hindsight, I should have looked into. So I temporarily disabled the policies and was able to run the script successfully.