We are not sure for translation issue.
We didn't use "TranslatePress " before. So we don't know how does it work.
In originally, __( 'Sample Text', 'text-domain' ) php code will be generated "Sample Text" string on pot file to translate like screenshot.
Then, translator plugins will get the string from pot file and translate it. So there is no issue on theme code.
We think this problem is caused by translator plugin or text cache.
Please clear all browser cache and try again.
If it doesn't work, please contact the TranslatePress plugin team directly.
They can provide the solution for their plugin. Or please change the translator plugin.
We use loco translator and it works well without any issue.
Best Regards, C-Themes