windows - Cygwin Mintty unicode doesn't display fail despite having dejavu sans mono and everything

Edit

the problem is ubuntu machine can't display \u03bb as greek lambda symbol

ubuntu is remote:

[ubuntu@ubuntu:~]$echo -e "\xce\xbb\x0a" 
λ 

[ubuntu@ubuntu:~]$echo -e "\u03bb" 
\u03BB 

this is local:

matizmabel@Casper ~ 
$ echo -e "\u03bb" 
λ 

matizmabel@Casper ~ 
$ echo -e "\xce\xbb" 
λ 

matizmabel@Casper ~ 
$

I use cygwin mintty terminal.

I use Dejavu Sans Mono and this:

$ locale
LANG=en_US.UTF-8
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_ALL=

I ssh into ubuntu headless server, and have this issue. Please fix my unicode display problem.