aaPanel installs everything from the aaPanel repository but the fault is always on the OS.
I also have a similar issue with Wordpress installed on aaPanel, on CentOS 7.
All software was installed using the compiled method.
The REST API is one way WordPress, and other applications, communicate with the server. One example is the block editor screen, which relies on this to display, and save, your posts and pages.
The REST API request failed due to an error.
Error: cURL error 28: Operation timed out after 10001 milliseconds with 0 bytes received (http_request_failed)