Simple saml integration issue

Hi everyone

I am new one with elgg framework and trying to configure  simplesaml plugin. i am facing an issue i dont know i missed any configuration or not. 

After I done simplesaml configuration, its successfully redirecting to SAML IDP login page but after successful login again redirect to IDP login page. i think retrieved attributes and tokens are not sending to elgg application and may be authentication is still set to false but i can see all retrieved attribute in sqllite file.

i think my authsource.php conf is wrong or is there any other setting to forward received attribute from simplesamlphp to elgg?

really appreciated if anyone can help me.

 authsource.php

'attributes' => [
            'elgg:external_id' => 'urn:oid:1.3.6.1.4.1.5923.1.1.1.6',
'elgg:email' => 'urn:oid:0.9.2342.19200300.100.1.3',
'elgg:firstname' => 'urn:oid:2.5.4.42',
'elgg:username' => 'urn:oid:1.3.6.1.4.1.5923.1.1.1.6',
'elgg:auto_link' => 'urn:oid:1.3.6.1.4.1.5923.1.1.1.6',
  'uid' => 'urn:oid:1.3.6.1.4.1.5923.1.1.1.6',
'cn' => ['Test User'],