I have identified the issue for that particular user, As I already said we use public key method to auto login without asking for the password, there is the problem, his user account is being shared by another user, so his private key is not secure and ssh fails with below error

debug3: Bad permissions. Try removing permissions for user: XXXXX on f
+ile C:\\Users\\XXXXXX/.ssh/id_rsa.
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@         WARNING: UNPROTECTED PRIVATE KEY FILE!          @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
Permissions for 'C:\\Users\\XXXXXX/.ssh/id_rsa' are too open.
It is required that your private key files are NOT accessible by other
+s.
This private key will be ignored.
[download]

After removing the permission for the other user, it works fine.