脚本输出的明显限制

So I've got this really simple script:

<?php

for($n = 0; $n < 50000; $n++) {
    echo "a";
}

• If I run it on local server (xampp), the output I get is, as expected, 50.000 "a"s.
• But! When I run it on the web server it outputs only the first 24525 characters. Sometimes a bit more, but not much more. 90% of the time output is limited to that.

Target machine is a VPS which I have no control over. Cloudflare is also running in case that is relevant. I've got no idea what's causing this.

Is there any PHP setting that limits the output size? Or Cloudflare's? I didn't find anything at all about this anywhere online.

It's not a browser issue by the way, it happens at all browsers. Works every time at localhost, and fails at remote.

Edit: Max execution time, 15 seconds in the PHP config, is not reached, not by far. Thanks in advance for any reply.