We have set up a shop with Magento 2.1.7, all products were imported via the Rest API and everything in the backend looks good. Prices are shown on parent and child products. But in the frontend the price from the configurable products is 0,00€ (grid and detail view), if we choose a variant like color and size the product price switches to the correct price.
Does anyone have a idea where to look?

Reindex was already made.

Configurable Product
[![enter image description here](https://i.stack.imgur.com/yiD7p.jpg)](https://i.stack.imgur.com/yiD7p.jpg)

Variant choosen
[![enter image description here](https://i.stack.imgur.com/dBizL.jpg)](https://i.stack.imgur.com/dBizL.jpg)

Update:
It seems that Magento will take a special price for rendering, but there is no special price for the product. See HTML

```
<span class="price-container price-final_price tax weee"
 itemprop="offers" itemscope itemtype="http://schema.org/Offer">
        <span class="price-label">Sonderangebot</span>
    <span  id="product-price-6822"                data-price-amount="0"
    data-price-type="finalPrice"
    class="price-wrapper "
     itemprop="price" content="0">
    <span class="price">0,00 €</span>    </span>
            <meta itemprop="priceCurrency" content="EUR" />
</span>
</span>
<span class="old-price sly-old-price no-display">

<span class="price-container price-final_price tax weee">
<span class="price-label">Normalpreis</span>
<span  id="old-price-6822" data-price-amount="319.99" data-price type="oldPrice" class="price-wrapper ">
    <span class="price">319,99 €</span>    </span>
    </span>
</span>

```