Slick slider gets wrong width

My slick slider gets wrong width when initialized and when I change screen resolutions.

My js:

$('.slider').slick({
    infinite: false,
    speed: 300,
    initialSlide: 1,
    slidesToShow: 3,
    slidesToScroll: 1,
    dots: false,
    responsive: [{
        breakpoint: 1024,
        settings: {
            slidesToShow: 2
        }
    }, {
        breakpoint: 650,
        settings: {
            initialSlide: 2,
            slidesToShow: 1
        }
    }]
});

My css:

.sub-slider {
    width: 100%;
    display: flex; 
    flex-flow: column;

    .slider {
        display: flex;   
        flex-flow: row;
        justify-content: center;
        align-content: center;
        align-items: center;
        min-width:500px;

        .sub-box {
            text-align: center;
            padding-top: 45px;
            cursor:pointer;

            .title {
                color: #6deca0;
                font-family: "AmsiProNarw", sans-serif;
                font-size: 48px;
                font-style: italic;
                font-weight: 800;
            }
            .price {
                color: #393939;
                font-family: "AmsiProNarw", sans-serif;
                font-size: 18px;
                font-style: italic;
                font-weight: 800;
            }
            .sub-slider-btn {
                margin: 60px 20px;
                border-color: #eaeaea!important;
                background-color: #fdfdfd!important;
                color: #686868!important;
            }
        }

        .sub-box:hover { 
            transition: border .2s;            
            border-bottom: 14px solid #6deca0;
            .sub-slider-btn{
                border-color: #6deca0!important;
                background-color: rgba(108,235,159,.2)!important;
                color: #393939!important;
            }
        }
    }

    .sub-slider-confirmation-btn-wrp { 
        align-self: center;
        display: none;
        .sub-slider-confirmation-btn {
            cursor:pointer;
            $margin: 20px;
            $height: 45px;
            height: $height;
            width: 80px;
            border: 1px solid #ccc;
            border-radius: 8px;
            margin: $margin $margin $margin $margin;
            text-align: center;
            line-height: $height;  
            font-weight: 800;
        }
    }

}

This is how it is loaded, even though I have specified slidesToShow: 3.

Then when I change to resposive it looks like this:

I am not sure how to fix this. I have read through these, with no fix:

Slick slider wrong width on initialization

Slick carousel loads the wrong width on initialization

https://github.com/kenwheeler/slick/issues/790

https://github.com/kenwheeler/slick/issues/1180

https://github.com/kenwheeler/slick/issues/2167

edit:

I made a fiddle https://jsfiddle.net/simeydotme/fmo50w7n/

It seems to work in the fiddle, but not on my site. Maybe I inherit some bad css? But I've been trying to debug this for 5h now. And I cant find any solution..