Language problems.
WHY IT HAPPENS
Performance varies substantially by language.
Languages with less training data produce weaker results.
FOR NIGERIAN LANGUAGES
Coverage varies considerably. Test before relying on it.
WHAT TO TRY
Specify the audience and register.
"Translate for a general audience, informal register."
Prompt in English, request output in the target language. That frequently works better than prompting in the target language.
WHAT IT GETS WRONG
Idiom Cultural reference Register and formality Technical and legal precision
WHAT TO NEVER PUBLISH UNCHECKED
Marketing material Legal or contractual text Safety or health information
HAVE IT REVIEWED
By a native speaker, before publishing.
A translation that is grammatically correct and culturally wrong damages you.