I have made a simple custom module in Drupal 8, in which I use a settings file (config/install/my_module.settings.yml)
I have one entry, let's say
module: key: 'qsdqsd'
So when I install the module, I can use this entry in my controllers. But if I need to modify anything in this file (adding an entry, for instance...) I can't use it in my controllers (config->get(module.new_entry) returns NULL) unless I uninstall then reinstall the module.
drush cache-rebuild did not help neither.
What am I missing?