The process for creating a github repository first creates a repository using the artifact-id of the project not the repository form value.
Then, the process uses the repository value...
So, a new repository is created with artifactId name but this one is empty as the starter tries to push after on form repository name.
Another issue linked to github is that the github export in case of OpenAPI selector is set, it exports an empty project as it is a standard project (do not process openapi endpoints).
User:Password credentials is deprecated since some times, updated to Personal Access Token on UI for clearer user UX.
Set also the default to personal repository not organization repo.