Log in with the elastic user works, because you have set the password for the elastic user with the elasticsearch-setup-passwords command and you're using the correct password. Expected behavior. Now, what is this "user created earlier which is used before xpack enble" and how was it created ?
We can only suggest changes if you share your current configuration with us. If we don't know what you use now, we can't know what you need to change 
Assuming that you are using the elasticsearch output plugin in Logstash, please read through our documentation where we explain what needs to be configured. If after reading that and performing the necessary configuration changes, you still have issues, we'll be glad to help further, but do take the time to read through the docs, I'm sure you'll find it enlightening and really helpful for your understanding.