ssh-keygen prompt the user if he/she want to override the existing file, but exit

[bingbing8]

Please answer the following

"OpenSSH for Windows" version
0.0.12.0

OS details
Windows Server 2012 R2 Datacenter

What is failing
ssh-keygen exits when it prompt the user to enter yes or no
Expected output
does not exit, but take user input
Actual output
C:>ssh-keygen -t ed25519 -P "" -f c:\openssh\id_ed25519
Generating public/private ed25519 key pair.
c:\openssh\id_ed25519 already exists.
Overwrite (y/n)?
C:>