ACF Extended is bundled with a custom merged version of the Classic Editor & Disable Gutenberg plugins. This module is a global setting which is applied to all post types.
The Classic Editor module is disabled by default. It can be enabled and disabled in the Settings UIPRO, or with the following code:
add_action('acf/init', 'my_acfe_modules');
function my_acfe_modules(){
// enable classic editor
acf_update_setting('acfe/modules/classic_editor', true);
}
add_action('acfe/init', 'my_acfe_modules');
function my_acfe_modules(){
// enable classic editor
acfe_update_setting('modules/classic_editor', true);
}