I developed an e-commerce and used a payment system from Checkout Cielo with PHP. Every time a user makes a purchase the server of Cielo sends a POST to my PHP page informing the data of the purchase.
Here is an example of how I retrieve the data:
$var1 = $_POST['var1_cielo'];
$var2 = $_POST['var2_cielo'];
Everything was working normally, until I migrated the application to another server and now the POSTS always arrive empty.
By the tests I performed the problem is always with POST is done by another server to my site because the forms within the site are working normally.