Odd issue to with Defining Constants

PHP
1

Hello I am testing things and i recently uploaded this code on a different hosting but for some reason it is not translating properly.

Here is the code:

/*
* --------------------------------------------------------------------------
* Static Language System
* --------------------------------------------------------------------------
* Loads correct language array depending on LANGUAGE setting.
*/

if(LANGUAGE === 'custom') {
    $config['lang_custom'] = include_once(LANG_PATH . 'custom.php');
    define('LANG', $config['lang_custom']);
} else {
    $config['lang_en'] = include_once( LANG_PATH . 'en.php');
    define('LANG', $config['lang_en']);
}

Language file:

<?php

return [
    'this' => 'this',
    'this1' => 'this1',
    'this2' => 'this2',
];

then on every page you can then go

<?php echo LANG['this']; ?> and it will echo ‘this’; but for some reason on this host it just shows an L, not errors nothing.

Can anyone see where/why this is happening? (again works on every other server i have tested)

Thanks