Hello,
I suppose that you placed translation to the author directory instead of the System or Custom https://prnt.sc/k9xbX-RwsuMQ . That’s why it was removed after theme/plugin update. You can recover that only if you have backup of your file.
You don’t need to translate it every time after the update if you place files in to correct directory as mentioned in the docs https://xstore.helpscoutdocs.com/article/30-base-theme-translation
Regards