Login Not Always Working

My logins don’t always work. I have the plugin installed, sometimes it works fine, but sometimes when I login with a test user account I created nothing happens. I login in, I get the redirected to the successful login page, but I’m not actually logged in. I’m using the antimatter theme and I added

{% if config.plugins.login.enabled and grav.user.username %}
    <li><i class="fa fa-lock"></i> {% include 'partials/login-status.html.twig' %}</li>
{% else %}

to my navigation.html.twig, so when I login, I will see “welcome username” in the navi bar menu. I also added

{% if config.plugins.login.enabled and grav.user.username %}
   <a class="muut" href="https://muut.com/i/mymutt">Real-time discussions right on your site</a>
   <script src="//cdn.muut.com/1/moot.min.js"></script>
{% else %}
   <p>You must be <a href="{{ base_url }}/login" target="_blank">logged in</a> to view the forums</p>
{% endif %}

to a page I created for a forum. Only users who are logged in can see it. I can tell I’m not logged because neither of these things works. And if I visit /log in I have to login yet again, and yet again nothing happens. As far as I know, these are the only two things I’ve used the login plugin for. Has anyone else had this problem? Everything of mine is updated on grav. Why would logins not be working? Something to do with cookies?

Check you’re using Grav 1.1 which comes with the latest Login plugin, and check if you can replicate it there too.