Azure On-Premises Data Gateway was installed with the wrong Azure scope settings in a virtual machine in Azure. After removing the local Data Gateway, the initial installation of the connection gateway will not be deleted, and a new one with the same name will no longer be created. I even tried removing the virtual machine to see if they disappear. This did not affect.
When I create a local data gateway in Azure Portal, I can still select the old installation names.
Also the following query returns these settings:
https://management.azure.com/subscriptions/{subscriptionId}/Microsoft.Web/locations/northeurope/connectionGatewayInstallations?api-version=2015-08-01-preview

I tried removing them using an DELETEhttp request to the connectionGatewayInstallations endpoint, but this returned 400 Bad Request:
https://management.azure.com/subscriptions/{subscriptionId}/providers/Microsoft.Web/locations/northeurope/connectionGatewayInstallations/{connectionGatewayInstallationId}?api-version=2015-08-01-preview
{
"error": {
"code": "DisallowedResourceOperation",
"message": "The operation 'delete' on resource type 'locations/connectionGatewayInstallations' is disallowed."
}
}
, - , GatewayInstallations?