overflow: hidden is causing white border with css transition

Question

I'm using this really cool css transition when i hover on a image. It works fine but sometimes there seems to appear white borders. When i don't use overflow: hidden, the borders are gone. But i need the overflow: hidden otherwise the transition doesn't work. (img is 500px w / 500px h)

Can anyone help me with this?

 .grid {
        position: relative;
        margin: 0 auto;
        overflow: auto;
        width: 100%;
        list-style: none;
        text-align: center;
    }
    /* Common style */
    
    .grid figure {
        position: relative;
        float: left;
        overflow: hidden;
        margin: 10px 1%;
        margin: 0;
        width: 25%;
        /*  background: #101224; */
        text-align: center;
        cursor: pointer;
    }
    
    .grid figure img {
        position: relative;
        display: block;
        width: 100%;
        opacity: 0.8;
    }
    
    .grid figure figcaption {
        padding: 2em;
        color: #fff;
        text-transform: uppercase;
        font-size: 1.25em;
        -webkit-backface-visibility: hidden;
        backface-visibility: hidden;
    }
    
    .grid figure figcaption::before,
    .grid figure figcaption::after {
        pointer-events: none;
    }
    
    .grid figure figcaption,
    .grid figure figcaption > a {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
    }
    /* Anchor will cover the whole item by default */
    /* For some effects it will show as a button */
    
    .grid figure figcaption > a {
        z-index: 1000;
        text-indent: 200%;
        white-space: nowrap;
        font-size: 0;
        opacity: 0;
    }
    
    .grid figure h2 {
        word-spacing: -0.15em;
        font-weight: 300;
    }
    
    .grid figure h2,
    .grid figure p {
        margin: 0;
    }
    
    .grid figure p {
        letter-spacing: 1px;
        font-size: 68.5%;
    }
    /*---------------*/
    /***** Sadie *****/
    /*---------------*/
    
    figure.effect-sadie figcaption::before {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: -webkit-linear-gradient(top, rgba(17, 18, 36, 0) 0%, rgba(17, 18, 36, 0.8) 75%);
        background: linear-gradient(to bottom, rgba(17, 18, 36, 0) 0%, rgba(17, 18, 36, 0.8) 75%);
        content: '';
        opacity: 0;
        -webkit-transform: translate3d(0, 50%, 0);
        transform: translate3d(0, 50%, 0);
    }
    
    figure.effect-sadie h2 {
        position: absolute;
        top: 50%;
        left: 0;
        width: 100%;
        color: #fff;
        /* color: #dd9a45; */
        -webkit-transition: -webkit-transform 0.35s, color 0.35s;
        transition: transform 0.35s, color 0.35s;
        -webkit-transform: translate3d(0, -50%, 0);
        transform: translate3d(0, -50%, 0);
    }
    
    figure.effect-sadie figcaption::before,
    figure.effect-sadie p {
        -webkit-transition: opacity 0.35s, -webkit-transform 0.35s;
        transition: opacity 0.35s, transform 0.35s;
    }
    
    figure.effect-sadie p {
        position: absolute;
        bottom: 0;
        left: 0;
        padding: 2em;
        width: 100%;
        opacity: 0;
        -webkit-transform: translate3d(0, 10px, 0);
        transform: translate3d(0, 10px, 0);
    }
    
    figure.effect-sadie:hover h2 {
        color: #dd9a45;
        ;
        -webkit-transform: translate3d(0, -50%, 0) translate3d(0, -40px, 0);
        transform: translate3d(0, -50%, 0) translate3d(0, -40px, 0);
    }
    
    figure.effect-sadie:hover figcaption::before,
    figure.effect-sadie:hover p {
        opacity: 1;
        -webkit-transform: translate3d(0, 0, 0);
        transform: translate3d(0, 0, 0);
    }
    
    @media only screen and (max-width: 1000px) {
        .grid figure {
            width: 50%;
        }
    }
    
    @media only screen and (max-width: 500px) {
        .grid figure {
            width: 100%;
        }
        .grid {
            padding: 0 5%
        }
    }

<div class="grid">
        <figure class="effect-sadie">
            <img src="img/2.jpg" alt="img02" />
            <figcaption>
                <h2>IMG ONE</h2>
                <p>Sadie never took her eyes off me.
                    <br>She had a dark soul.</p>
                <a href="#">View more</a>
            </figcaption>
        </figure>
        <figure class="effect-sadie">
            <img src="img/14.jpg" alt="img14" />
            <figcaption>
                <h2>IMG TWO</h2>
                <p>Sadie never took her eyes off me.
                    <br>She had a dark soul.</p>
                <a href="#">View more</a>
            </figcaption>
        </figure>

        <figure class="effect-sadie">
            <img src="img/2.jpg" alt="img02" />
            <figcaption>
                <h2>IMG THREE</h2>
                <p>Sadie never took her eyes off me.
                    <br>She had a dark soul.</p>
                <a href="#">View more</a>
            </figcaption>
        </figure>
        <figure class="effect-sadie">
            <img src="img/14.jpg" alt="img14" />
            <figcaption>
                <h2>IMG FOUR</h2>
                <p>Sadie never took her eyes off me.
                    <br>She had a dark soul.</p>
                <a href="#">View more</a>
            </figcaption>
        </figure>
    </div>