Hi,
Creating "breadcrumb" links are handled by Joomla Core, and joomla looks at the Itemid number to generate it. (basically the page/menu hierarchy is taken into consideration).
If there is problem with hierarchy then Joomla will fail to create the breadcrumb correctly. Beside, Virtuemart and Joomla doest work the same way to handle the hierarchy.
If the page page/menu is linked twice under different sections, Joomla gets confused and won't know what the correct flow is. Or Joomla can't know what product belongs to what VM category, because Virtuemart and Joomla don't talk each other. Result; you will end up with unexpected breadcrumb flow as you pointed out in your screenshots. This problem can't be solved with coding. It is all related to backend configuration.
But I have heard there are some 3rd party plugins to create breadcrumb specifically for Virtuemart if you have a complex page hierarchy, for example this plugin might be useful:
extensions.joomla.org/extensions/extension-specific/virtuemart-extensions/virtuemart-products-search/10329
It is a paid plugin, but there are some other free plugins available as well.
Regards,
Support