Hi,
you have created custom view for your article items by editing Article add-on custom view
This is the code of your custom view
<div class="acymailing_content"><a href="{link}" target="_blank" name="content-0">
<h2 class="" acym_title">{title}</h2>
</a>{picthtml}<div class="acydescription">{intro}</div><br /></div>
Once I removed that custom view, item article truncation started to work again