A user, vulkanino, reported an issue with Onebox text not being translated on their Discourse installation. They shared screenshots showing that the “Reading time” string at the bottom of the Onebox is in English, even though the translation is available. codinghorror suggested reaching out to techAPJ, who built the Onebox feature.
techAPJ replied that the translation should be working and asked vulkanino to check their instance’s translation settings. vulkanino confirmed that their instance is fully translated, but techAPJ suggested that the “Set locale from accept language header” setting might be the cause. vulkanino disabled the setting, but the issue persisted.
techAPJ advised vulkanino to onebox the topic again by adding ?1 to the URL to see the translated Onebox in action.
and noticed that translation is not working at all. Notice the Sign Up / Login button text, footer notice. Everything is in English. Why is that? Once we figure that out the original issue you reported should be fixed.