[已解决] Translate strings that are not in default language

Background of the issue:
I am trying to translate a string from my custom WordPress theme using WPML. The string is registered like this in the theme: . My site's default language is Lithuanian, and the language of domain for 'theme' strings is English. I have provided the Lithuanian translation for the string in WPML's String Translation. I have added debugging code to the gettext filter and confirmed that icl_translate() correctly returns the translation ('Susisiekite su mumis').

Symptoms:
On the frontend, the original English string ('Contact us') is displayed instead of the Lithuanian translation. The filter function outputs: Original Text: Contact us, Translated Text: Contact us, Translation via icl_translate: Susisiekite su mumis.

Questions:
Why is the Lithuanian translation not applied in the frontend?
Is there a specific configuration needed for WPML to apply translations correctly?