Steps to reproduce the issue

server1: backup database and joomla files
mysqldump joomla -uroot -p > /tmp/joomla.sql
tar czvf joomla.tar.gz joomla

When I can connect to administrator in server1
with a wrong login/password, there is a warning in yellow
"Warning
Username and password do not match or you do not have an account yet."
I can connect to administrator with a good login/pass
The front-end is OK (database connection OK)

server2: restore database and joomla files to another server
mysql -u root -p joomla < /tmp/joomla.sql
tar xzvf joomla.tar.gz
I can't login to administrator with good login/password. it reloads administrator/index.php with the login form.
And with wrong login/password, there is no warning!!!
The front-end is OK (database connection OK)

Expected result

the same result as server1 on server2.

Actual result

Does joomla configuration depends on hostname?

System information (as much as possible)

mysql 5.6.25
php 5.4.16
joomla 3.4.1

Additional comments

Thanks for your help!