h2 section title “On Sale Products” not translating. (StoreFront)

This is really frustrating. Using Dutch Language, playing around with the default installation of StoreFront. It doesn’t seem to translate the section titles properly and I can’t find out what’s going on here. For example: The output code:
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<section class="storefront-product-section storefront-on-sale-products" aria-label="Producten in de uitverkoop"><h2 class="section-title">On sale Products</h2>
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The aria-label is fine, translates well, but the content in the h2 section-title doesn’t translate. As said, tried to find this in the code, but no luck. In storefront-template-functions.php found in storefront/inc/ the only reference I could find was this:
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echo '<section class="storefront-product-section storefront-on-sale-products" aria-label="' . esc_attr__( 'On Sale Products', 'storefront' ) . '">';

				do_action( 'storefront_homepage_before_on_sale_products' );

				echo '<h2 class="section-title">' . wp_kses_post( $args['title'] ) . '</h2>';

etc…
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As you can see, aria-label is translated correctly but between the h2 section-title tag it says: wp_kses_post( $args['title'] )

Where do I translate this? What am I not seeing? How’s this done?

Very eager for an answer, anyone?

Thanks in advance, much appreciated,

Regards,

Niels

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