Hi @Nathan Moebus how long has it been since you deleted your custom domain? After deleting a custom domain, there can be a 20-minute delay for the change to propagate. Sometimes, it might take longer due to various factors.
If it's taking longer to delete, you can try using the Azure CLI to remove the custom domain. Open your terminal or command prompt and execute the following command:
az staticwebapp hostname delete -n <my-app-name> -g <rg-name> --hostname <app-custom-domain>