Ask for Wordpress Admin login, then open Plugins > Editor and edit  codistoconnect/connect.php in the MarketPlace Connect by Codisto plugin

Find:

public function proxy()

Inside that function find:

	if(!$acceptEncoding|| ($zlibEnabled==1||$zlibEnabled=='ON'))

Change it to:

	if($this->overridecompression || (!$acceptEncoding || ($zlibEnabled == 1 || $zlibEnabled == 'ON')))

Then scroll to the very top and find:

	final class CodistoConnect {

And add:

	private $overridecompression = true;

That will force the content to be decompressed regardless of $acceptEncoding or $zlibEnabled