Issue with Codeignter3 with network calls functions

Hello,

I haver tried both functions on CI2 and CI3 and found there is an issue with CI3.
On welcome controller I have added index2 method and execute it.
public function index()
{
$this->load->view('welcome_message');
}

public function index2()
{
for($j=0;$j<=10;$j++){
echo file_get_contents("https://google.com");
}
}
While the index2 is executing on CI3, I wasn't able to access any other function on the controller unless it finishes the execution, When I access index() as example the browser keep waiting until the execution of index2 finishes the it load the page.

I tried same to do the same thing on CI2 and it worked without any issue.

Could you please check what could be the issue.
Thanks