China optimised route AS4837 in our Seattle location is currently suffering congestion at peak time. We are awaiting a resolution date.
This was resolved by China Unicom although their network is not performing perfectly.
We originally had a suggested fix date of 2nd December but this has come and gone and issues have not been resolved yet, although we did see an improvement on 3rd December peak time. We're awaiting an update, the issue appears to affecting all hosting providers using AS4837 so is likely a China Unicom fiber cut/router issue.