In menu and HTML source you should always use the original link format
"index.php?option=..."
The appropriate Joomla SEO handler (either built-in Joomla router, or JoomSEF) will then convert the links into the correct format.
You should never use the SEO format or semi-SEO format, such as the example you gave: "MYSITE/our-products?page=shop.browse&category_id=83" as then it cannot be processed automatically e.g. if your settings or preferences change.
I guess in your case, you are mixing functionality of built-in Joomla SEO router with JoomSEF.
If you are using VirtueMart, you should simply
1) install JoomSEF
2) install VirtueMart SEF extension for JoomSEF
3) keep all links in menus or articles as "index.php?..."
and then everything should be working just fine.