CentOS 6.10: ASP0011W passwd(NDS): Sorry, incorrect password

I’m using SuperPuTTY version 1.4.0.9 on Win10 to connect to remote Linux box via SSH.
Today I got "Your password has expired" warning. On all the previous occasions I was able to change password without any issues.
But this time I got this:

WARNING: Your password has expired.
You must change your password now and login again!
Changing password for user user.
Current eDir Password:
New eDir Password:
Re-enter New eDir Password:
ASP0011W passwd(NDS): Sorry, incorrect password
Retype new password:
passwd: all authentication tokens updated successfully

On the penultimate line I retype the new password and the last line suggests that it has been changed successfully – however, I immediately get PuTTY warning "Connection closed by remote host" (this never happened in any of my previous password change attempts).
So at this pint I try to reconnect and login with the new password – but when I type in the new password and hit Enter I get fatal error in PuTTY "Remote side unexpectedly closed network connection".
Then I reconnected again and tried to login with the old password – and got "WARNING: Your password has expired." and I was again being asked to create a new password.
The other unusual things that I noticed with regards to this situation is that I never saw the term "eDir" at the password change prompt. Also, in the past, if I happened to mistype my new password, I don’t remember ever seeing "ASP0011W" – this is something new to me. And the last unusual thing – the password to the server would always expire in 90 days – but in this situation only 1/2 month has passed since the last time I changed the password.
I also made sure that the new password has never been used before and complies with all the security rules, like at least 14 characters, including capital letters, numbers and special characters.
Any ideas what might be happening here and how could I resolve the issue?