If you use the Drupal's admin in another language than the default language when enabling module or adding field or making any new translatable config, you risk having different langcode in your exported configuration. Most of the time you don't want that.
I think we can help the user to avoid that. A simple warning?
Or perhaps in the installer we can be clearer about what is the default language, and give an option to force configuration always to be saved first in the default language.
Another way would be to lock the language in administration by default in the default language and warn the user of potential side effect if he wants to change this setting.
For the end user is sometimes hard differentiate between configuration and content.
Peoples that did that by mistake:
https://wunder.io/blog/drupal-8-translations-best-practices
https://drupal.stackexchange.com/questions/223665/how-to-change-default-...