My server set up shadowsocks-libev, but the client speed is not matching.

admin

2G2H10M Hong Kong Server with Shadowsocks-Libev
I connected to the Hong Kong server via SSH and ran Speedtest. Upload speed was 12Mbps, not a false claim.
Then I connected my client to my node. It's very slow, so I tested the download speed. It ranged from 0.5MB to around 2MB.
What's going on? Watching YouTube and browsing Google is extremely laggy.