Firefly returns "One or more words violate Firefly user guidelines. Please edit and try again." with a picture of a very cute monkey. However, Xi Jinping riding

Firefly returns "One or more words violate Firefly user guidelines. Please edit and try again." with a picture of a very cute monkey. However, Xi Jinping riding a bike works just fine, although, the results look nothing at all like Xi Jinping riding a bike.