The "Project slug" field does not get filled with the "Project name" field when creating a project using a template with the new experimental UI

Summary

The "Project slug" field does not get filled along with the "Project name" field when creating a project using a (built-in, instance or group) template with the new experimental UI.

Steps to reproduce

1. Turn on the feature flag new_create_project_ui_experiment_percentage
2. Go to "Create a new project"
3. Click "Create from template"
4. Select a template such as "Ruby on Rails"
5. Fill in the project name.

You will notice that the "Project slug" is not getting filled.

What is the current bug behavior?

The "Project slug" field does not get filled when the "Project name" is typed.

What is the expected correct behavior?

The "Project slug" field should get filled automatically when the "Project name" is typed.

Relevant logs and/or screenshots

project_slug_bug