DeepL, for example, fails hilariously with certain inputs. I once got it to mistranslate things like these:
- "孔明" (Kongming, the genius strategist/statesman from China's Three Kingdoms period) got translated as "Confucius"
- "chage and aska" (a Japanese pop music duo) got translated as "曹操" (Cao Cao, founder of the Wei state during China's Three Kingdoms period) or even "ちんちん" (literally "penis" in Japanese)