Russia was under no obligation to keep Snowden instead of letting him continue to Ecuador. Putin just wanted to use him as a bargaining chip with the U.S., but the U.S. understood that all his documents were already public, so Putin hasn’t been able to play that card well yet.
It was revoked before he left China. https://apnews.com/general-news-587786e6e63b4dc2b70c471606d7f584
That didn’t stop China from ignoring his asylum request following his release of documentation of hacked Chinese systems and kicking him out of the country because whether you have a valid passport doesn’t matter for geopolitical issues. https://www.scmp.com/news/hong-kong/article/1259508/edward-snowden-us-government-has-been-hacking-hong-kong-and-china
Russia was under no obligation to keep Snowden instead of letting him continue to Ecuador. Putin just wanted to use him as a bargaining chip with the U.S., but the U.S. understood that all his documents were already public, so Putin hasn’t been able to play that card well yet.