Can not use Proxy Server socks5

[mandsun]

Background:
I want to download bt files from an IPV6 site, but I do not have a real IPV6 address. So I use a VPS(has IPV6 address) as a transit server.
I use Qv2ray to establish the connection. And when I use Utorrent, after setting, it works very well!
The settings can be seen in the attachments.
Utorrent: preference---connection---Proxy Server---type:socks5, Proxy:127.0.0.1, Port:1439.
Qv2ray: Listening Address:127.0.0.1--Socks setting---Port:1439,UDP support:enable, UDP local IP:127.0.0.1

Problem:
When I use qBittorrent, I also changed the proxy settings, but it does not work! the client can connect to the seed, but no download speed!
The settings can be seen in qbittorrent.png, the qBittorrent-client.png is the shortcut of the client.
Options--Connection--Proxy Server---Type:sock5, Host:127.0.0.1, Port:1439--Use proxy for peers connection:enable---use proxy only for torrents:enable or disable I both tried.

Could anyone help me? What other settings I should do?
Thank you very much!!

[hbwbf]

The same problem as yours. Better post your question on the GitHub issue page: https://github.com/qbittorrent/qBittorrent/issues.