Contact Form 7 arrows keep on spinning when Permalink enabled as ‘Post name’

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;