It seems there's an issue when I attempt to renew my membership. Last time I paid for the service must have been 1 year ago, perhaps more.
As shown on the screenshot, it says my membership is still active (but isn't). There's no button to renew it. When I try to cancel it to renew from scratch, the membership comes back whether the website tell me I've successfully cancelled it. One strange fact is that it tells me my membership will remain active until October 15 2019 each time I cancel it.