Hi,
The translation files not being loaded just means that Joomla didn't find the translation file. But it can be totally normal. It's just that the extension don't have a translation file for itself. For example, for the datepickerfield plugin listed as not loaded on your screenshot. But that's just because the translations used by that plugin are in the translation file of HikaShop.
The latest version of the translation file is not 4.2.2 but 4.3.0. But yes, the NL translations were not updated since the 4.2.2, only the new translations were added, with their english text.
Now you didn't give a link to your website so I can't check the situation there.
It's possible that your website is actually not in Dutch but in English on the frontend. And thus, only the English translation files are loaded there. That would explain why you see the text by default in HikaShop in Engilsh, while the content you've added yourself is in Dutch.
In that case, the problem is not the translation files but how the languages are configured in Joomla.