Critical issue: The Rest API encountered an error

Hello,

I installed the Site Health Tool and got this message:

The Rest API encountered an error

The REST API is one way that WordPress and other applications communicate with the server. For example, the block editor screen relies on the REST API to display and save your posts and pages.

When testing the REST API, an error was encountered:

REST API Endpoint: https://mydomain.com/wp-json/wp/v2/types/post?context=edit

REST API Response: (http_request_failed) cURL error 28: Operation timed out after 10015 milliseconds with 0 bytes received

I deactivated while troubleshooting all the plugins and turned on a standard theme (twenty-twenty), but the problem still persists.

Help or a hint, where to find help, greatly appreciated.

Thanks,
miednr