Windows Terminal version (or Windows build number)

Windows Terminal Version: 1.9.1942.0

Other Software

Bug is seen in Emacs 27.2 too in WSL

 wsl --list -v
 NAME            STATE           VERSION
 * Ubuntu-20.04    Running         2

Steps to reproduce

ctrl underscore got by pressing ctrl and _ (underscore)key sends RET in terminal as well as emacs in WSL. ubuntu 20.04

 $uname -a
 Linux CompName 5.10.16.3-microsoft-standard-WSL2 #1 SMP Fri Apr 2 22:23:49 UTC 2021 x86_64 x86_64 x86_64     GNU/Linux

$ showkey -a

Press any keys - Ctrl-D will terminate this program

_        95 0137 0x5f
^M       13 0015 0x0d
^D        4 0004 0x04

Expected Behavior

In Emacs Ctrl + _ is usually mapped to undo. It seems to be mapped to RET in emacs as well as terminal as reported above

Actual Behavior

getting RET passed to terminal and in emacs instead of _ or undo in emacs