Missing translation errors not shown correctly after adding a new language

Steps to reproduce:

• Open the attached test project
• import attached translations
• Run translation test for the currently open file (Screen01.ui.qml)
• -> No issues found, as expected
• Add Chinese language but don't add any translations for it
• Run translation test again
• -> 2D View and translation_report_Screen01.json should now report missing translations, but instead no errors are found
• Run the tests again
• -> Results now as expected