posts blocks don’t show up correctly

On the broken page, your per-item div looks like

<div itemscope="" itemtype="" class="edd_download"
     id="edd_download_28068" style="width: 33.3%; float: left;">

That width: 33.3% is wrong: the containing <div class="edd_downloads_list edd_download_columns_3"> already does the three column layout, so this extra width style means each item should only use a third of the width of the column. You need to work out where this is coming from in your templates and remove it.