This is my translation file in a custom extension:
I changed one translation in that file and afterwards I executed this to gather the translations:
php bin/magento i18n:collect-phrases -o app/code/FireGento/MageSetup/i18n/de_DE.csv app/code/FireGento/MageSetup/
I also cleared the cache, but the translation is still the old term. Is that the wrong approach?