When not using default language and let the CP remain in the default language results in some headers within the CP showing their tag instead of their intended string. On License Keys page it shows CP.ITEMS and CP.STATUS, on Manage Taxonomies page it shows cp.taxonomies.

I know this was an issue I had before with my first Statamic site beginning of 2018, and can't remember how I fixed it. But it seems that I need to do something more...

For this site I use one language; Dutch. I installed using statamic new [site] and then followed the steps after the clear:site command. I updated index.php with $locale = 'nl';. Then I changed locale in the settings.yaml:

locales:
  nl:
    full: nl_NL
    name: Dutch
    url: /

I don't have files in lang folder because the CP doesn't need translation.

When I change the settings.yaml into the default all CP headers show up correct.