Exact same issue happened to me as well. It was a Chinese iOS developer. Did an OK job, was planning to give him good reviews anyways, until he gave the condi

Exact same issue happened to me as well. It was a Chinese iOS developer. Did an OK job, was planning to give him good reviews anyways, until he gave the condition to leave a 5-star review or no code. Got in touch with his team leader and matter was resolved quickly. Ended up leaving a negative review. Generally, had very positive experiences with Upwork and other platforms including Freelancer.com which I no longer use anymore.