Please be sure to change the nameservers of your domain. This is not the same as adding NS records to your domain’s DNS. With most domain providers, DNS settings and nameserver settings are different options.
If you’re not sure how to do that, your domain provider can probably help you more effectively than we can, because this is a setting that needs to be changed on their end. But you can also share your domains here so we can check if they are setup correctly.