CSS and HTML (django)

Hey so i have this CSS

.welcome_box{
background-color: aqua;
min-height: 50px;
min-width: 50px;
padding: 20px
}`

and in the html

       <div class="welcome_box" >
            <div class="center"  >
                <a href="{% url 'login'%}">
                    <button class="button">Log In</button>
                </a>
            </div>

            <div class="center">
                <a href="{% url 'signup'%}">
                    <button class="button"> Sign Up</button>
                </a>
            </div>
        </div>

and the rel <link rel="stylesheet" href="{% static 'welcomepage/styles/css/mycss.css' %}"> however the CSS does not seem to take effect on the page, for some reason its only this class as the rest are working. I don't do much html and css so it may be something very basic.

Edit: Inline CSS seems to work fine but again, the other classes from the same css file do take effect