Session object losing one column value

Hi all.

I have a login method on user controller that register the user object in the session with the code bellow:

        $request->session()->put('user', $user[0]);
        $request->session()->save();

And I can retrieve that object in a blade view with no problems, but the ID field of the user object becomes empty.

Some info that could be usefull:

• all other columns works fine;
• ID is the only integer column;
• if I put the ID value alone in a session var still doesn't work as well;
• if I put the ID value alone in a session var and converted to string, then it works.

Some of you faced this before? What am I doing wrong? If you need some more details, please let me know.

Thanks in advance for all support.