That is really happening. I made test in PHP to confirm this.
I created a test.php file and put:
<?php
error_log('Downloading...');
header('Content-type: application/force-download');
header('Content-Disposition: attachment; filename="test.txt"');
echo 'test android download';
?>
So, when I open www.myurl/test.php via any Android mobile browser, in the error_log.log I get "Downloading..." two times.
When i open same URL in any other Mobile OS(Windows, IOS, etc.) I get only one time "Downloading..." in error_log.log file.
Does anyone know what's going on and how to avoid this ??
This is a big problem for me, because I perform user charging when somebody download a file. And now from Android Phones there are 2 charges for 1 downloaded file.