ProxyProtocol does not work when backend is BungeeCord

[Lunac-dev]

Describe the bug
Server information (motd,version,etc) is not returned when there is a BungeeCord behind Ultraviolet and ProxyProtocol is enabled.

System
Ubuntu 18.04
Ultraviolet v1.1

To Reproduce
Steps to reproduce the behavior:

1. Enable the ProxyProtocol setting for Ultraviolet.
2. Specify BungeeCord.
3. Enable ProxyProtocol for BungeeCord.
4. Connect to the Ultraviolet.

Expected behavior
Server information such as MOTD is returned.

Screenshots
The connection succeeds, although it appears to be offline.

Additional context
Console has a ping from Ultraviolet, not a ping from the player's IP.

BungeeCord Console:
InitialHandler - read timed out

Ultraviolet:
error while trying to read: reading the content of the packet failed: unexpected EOF
error while trying to read: proxyproto: proxy protocol signature not present

In Spigot, the server information is returned successfully and the ProxyProtocol works.