Phpinfo() In Admin Panel Returns 404 Error

When the calling phpinfo() from the Admin panel (url: https://www.myshop.com/admin.php?dispatch=tools.phpinfo) a 404 error is returned to the browser.

However, I created a text file with just the contents: and placed it in the root directory of my CS-Cart installation. Calling this URL: https://www.myshop.com/nfo.php returns the full phpinfo() results.

Any ideas on why this would fail from within CS-Cart but not when called directly?

Some add-ons (e.g. Twigmo) seem to make calls to phpinfo() and they are failing due to this error.

CS-Cart version 4.24

PHP version 5.3.27

Thanks.

We're narrowed the problem down to what we think is an issue with PHP permissions.
We've found that PHP scripts in some directories can be executed, but not in others.
For example, we created a simple "Hello World" script and placed it in 2 directories that have the same ownership and directory/file permissions:
https://www.myshop.com/support/hello.php
returns "Hello World", but
https://www.myshop.com/app/hello.php
returns a 404 Page Not Found error.
The hello.php file fails to execute in any of the CS-Cart directories, but does execute in new top-level directories that we create. We confirmed that the directory privileges and ownership are the same for all directories.
Can anyone with more PHP configuration experience than us comment on what might cause this? It is hosted on a shared server so we don't have direct access to the Apache/PHP configuration files.
Thx.

app folder is protected with ".htaccess", it does not allow to run PHP scripts .

Our hosting company discoverd a problem with the sqlite pdo shared library that was causing a problem when the phpinfo function was called on our server. This has been resolved and phpinfo is now executing properly and our store is working correctly also.