Problem Description
- Contact Form 7 forms only work when logged in
- When logged out, in your Javascript Console you see things like /wp-json/contact-form-7/v1/contact-forms/###/refill with a 401 error
This is caused by a plugin or server configuration which is blocking access to the WP-JSON REST API endpoint.
Resolution
- Look for plugins that limit access, such as the "Password Protected" plugin or "Disable REST API" plugin
- Find options to enable REST API access, either generally or specifically for the CF7 endpoints.