Having a very bizarre problem. I have a PHP script on a website that runs perfectly fine when I enter the URL into the browser in normal mode. However, when I do the exact same action in incognito mode, it's as if I did nothing. The script won't even echo a line at the very top of it to indicate that it ran at all. The same situation happens in Firefox private mode as well.
Does anyone know what's wrong?
There is no connection between the incognito mode browser and how the server interprets the php code. What the mode could bring to the table is cache. There could be a chance you were running a cached version of your website (unlikely).
Make sure you are accessing the correct IP/Domain with the appropriate port.
Edit: Also check if the file you are modifying (it may sounds stupid but it happens frequently) is the same as the one you are accessing.