[Closed] Strings missing for a specific plugin

Background of the issue:
I am trying to translate strings from the user panel on my website, which comes with the functions plugin. I have scanned for strings in theme and plugin localization. The system found 3,000 strings, but they are still missing from string translation. I also tried looking for strings while pages are rendered, but with no luck. Link to a page where the issue can be seen: hidden link

Symptoms:
Strings for translation are not to be found.

Questions:
Why are the strings missing from string translation?
How can I ensure that all strings are available for translation?