Dear Stefan,
In the Manual, under '
Plug-in Options / Strict Mode', there is a note saying:
NOTE: The standard Joomla! 'Remember Me' log-in function will be disabled by the plug-in, because the ‘Remember Me’ function by-passes the session record keeping and is therefore not compatible with the plug-in.
The
Remember Me function allows you start a second Joomla! session without entering your credentials, while the default Login One! plug-in purpose is all about NOT allowing two concurrent sessions. For this reason, the
Remember Me function is in conflict with the principle of the Login One! plug-in and therefore, the
Remember Me function is disabled.