Admin user created via pam authentication not able to query password protected bucket

1. create a password protected bucket test with some password.
2. Query using curl command with user Administrator and password as password as:
This behavior is correct:
[root@localhost bin]# curl --user "Administrator" -H'Content-Type:application/json' http://127.0.0.1:8093/query/service -d '

'
Enter host password for user 'Administrator':
{
"requestID": "0656f67a-d405-45da-8e89-ea8d4a731c85",
"signature":

,
"results": [
{
"test":

}
],
"status": "success",
"metrics":

}

3. make sure you enable pam on this system using:
https://developer.couchbase.com/documentation/server/current/security/security-pam-auth.html

4. create a user in UI with admin username and role as admin.
5. Give a password to this user through useradd and passwd commands.

[root@localhost bin]# useradd admin

[root@localhost bin]# passwd admin

Changing password for user admin2.

New password: 

BAD PASSWORD: The password fails the dictionary check - it is based on a dictionary word

Retype new password: 

[root@localhost bin]# passwd admin2

Changing password for user admin2.

New password: 

BAD PASSWORD: The password fails the dictionary check - it is based on a dictionary word

Retype new password: 

passwd: all authentication tokens updated successfully.

6. Try issuing the same query with admin username:

[root@localhost bin]# curl --user "admin2" -H'Content-Type:application/json' http://127.0.0.1:8093/query/service -d '

'
Enter host password for user 'admin2':
{
"requestID": "4f4b3e2d-c257-44e2-8dec-311c74f44fd0",
"signature":

,
"results": [
],
"errors": [

],
"status": "stopped",
"metrics":

}

Attaching logs.