Thank you for your explanation.
The 404 page is the JohnCMS styled 404 page, not the web server's default 404 page.
Unfortunately, I am using shared hosting, so I do not have SSH/CLI access and cannot run:
php system/bin/console router:list
Since the request reaches JohnCMS, does this mean that my routes.php file is not being loaded?
Is there another way to verify that the module routes are being registered without using the CLI?
Thank you again for your help.