I see problem.
From menu i have link to categorry:
index.php?option=com_virtuemart&view=category&virtuemart_category_id=65&virtuemart_manufacturer_id=0&Itemid=759
and JoomSef make sef-url /category
but when i go into category page I see in duplicity:
index.php?option=com_virtuemart&view=category&virtuemart_category_id=65&Itemid=759
and JoomSef make second and duplicity url /category2
Two identical urls are generated per category page, but one does not contain manufacturer 0
I think that problem is in orderby-displaynumber part.
How I can repair it?
Hmmm manufacturer_id is automatically 0, if not given. How does the standard routing handles it?
When I make menu manual menu item links to VM categories in Joomla
Joomla stores:
index.php?option=com_virtuemart&view=category&virtuemart_category_id=78&virtuemart_manufacturer_id=0
Everything works as expected - no duplication.
Looks like a joomsef issue to me.
I will prepare a test copy of the website and turn off everything safe. we will test it.