I had used Contact Form 7 plugin on various WordPress sites, but did not experience this problem before.
A client complained about forms not working and arrows keep spinning infinitely (on some pages it worked while not on others).
With the default Permalink setting (which is ‘?pageid=X’), all forms worked.
With the Permalink set as %postname%, some forms stopped working.
The following hack resolved the issue:
Go to Dashboard–>Plugins–>Contact Form 7–> Edit
Replace the line $url = wpcf7_get_request_uri(); in the file /includes/classes.php with the following:
global $post;
$url = ‘/index.php?page_id=’.$post->ID;
Thank you very much! You solved my problem.