@Padraig Foley As mentioned by community member, its not recommended to create any resources in resource group created by backup.
As a Global administrator, you can manage all aspects of Azure AD and Microsoft services that use Azure AD identities. But you will not be able to create or update resources.
To create a resource group, you need to have at least the "Contributor" role on the subscription or resource group level. This role allows you to create and manage all types of Azure resources within the resource group. You can also be assigned a custom role that includes the "Microsoft.Resources/subscriptions/resourceGroups/write" permission. This permission allows you to create resource groups.