Ok, Codestyling + Preserver or LocoTranslate with global setting, is what we recommend.
However it is important to understand why this happens and how you can fix it :
a. Translation files are flat files which keep index and translation string and translated string. like : index - String - Translated string (123-Take this course - Faça este curso)
b. The indexes are generated based on location of the translation text found in code.
c. When we add a new feature to a code, we add new translation strings and the indexes update.
d. So, the translations do not apply correctly due to index mismatch.
In which case all you need to do is "rescan" the translation files in Codestyling or Loco-translate plugin and you're done.
let me know if rescanning of translation files does not resolve the issue.