Place Ecwid product description on the left side
Ecwid have been enabling some new store layout option recently, and I think on Wix, the default now is for the product descriptions to be on the right side under the options and buttons. I believe Ecwid will soon be addin more options to change the layout of storefronts, but for now, you can try adding the following code to the advanced settings of the Ecwid app for Wix:
<script>
window.ec = window.ec || Object();
window.ec.storefront = window.ec.storefront || Object();
window.ec.storefront.product_details_two_columns_with_right_sidebar_show_product_description_on_sidebar = false;
Ecwid.refreshConfig();
</script>
That should put the description (which includes the tabs) on the left side under the product images where it always used to be.
The Ecwid API docs have lots more of these store layout customisations. See here