Instead of using Widget Shortcodes ( so you can remove that plugin ) do this:
1. Create a new Hook Element.
2. Add this code:
<div class="breadcrumbs" typeof="BreadcrumbList" vocab="https://schema.org/">
<?php if(function_exists('bcn_display'))
{
bcn_display();
}?>
</div>
3. Select the after_entry_title
hook
4. Set Display Rules to Posts > All Posts
If you want to include the breadcrumb on Pages then include them in the Display rules and change the hook to after_entry_header
You can see the hooks and their positions here:
https://docs.generatepress.com/article/hooks-visual-guide/