NSG Rules bulk deletion not working -programmatically and manually

I created a 8 NSG Rules and selected 6 --> delete. ooks like even via portal unable to delete the NSG rules as a bulk as it threw error-

[Refer here for more details on this error](https://github.com/terraform-providers/terraform-provider-azurerm/issues/11521#issuecomment-854504141)

Start with the linked Terraform issue and the reported Azure portal error, then compare the programmatic and manual bulk-deletion paths for NSG rules. Done means selecting multiple NSG rules and deleting them succeeds without the reported error; the payload names no repository files or tests.

Written by the indexing model from the issue text.