Please read our documentation – https://xstore.helpscoutdocs.com/article/30-base-theme-translation
Likely you simply need to synchronize translation files.
Button Sync (Loco Translate plugin http://prntscr.com/glemdq) allows you to synchronize your translation file with updated pot file. It means if we made any changes in template files that may affect transaltion or we added new string for the translation and you updated theme you need to synchronize your translation with updated files. Only after synchronization, you’ll be able to translate new strings or strings that were changed.
If the problem won’t be solved even after synchronization, please provide wp-admin and FTP access in Private Content.