i18n key sightly issue

I am using i18n, however it prints only key name not the value

here is my tag

<meta data-sly-test="${'ll_meta_test_content' @ i18n}" name="ll_meta_test_content" content="${'ll_meta_test_content' @ i18n , locale=request.locale}" />

here is my i18n node with value

Some test content

In the generated html I see meta tag as

<meta name="ll_meta_test_content" content="ll_meta_test_content"/>

It doesn't print key name instead of key value

My Site is set to English in Site Properties

My key node

My en node has jcr:language and jcr:mixinTypes defined