Can't reproduce.
Code:
bash-3.2$ php -v
PHP 7.4.27 (cli) (built: Dec 16 2021 18:12:35) ( NTS )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies
with Xdebug v3.0.2, Copyright (c) 2002-2021, by Derick Rethans
with Zend OPcache v7.4.27, Copyright (c), by Zend Technologies
bash-3.2$ php spark make:controller Myex --suffix --force
CodeIgniter v4.1.9 Command Line Tool - Server Time: 2022-03-15 05:45:26 UTC-05:00
File overwritten: APPPATH/Controllers/MyexController.php