After updating VM to 4.4.0 11095, when switching the language on the Product page, the transition is not to the same page with a different language. In the URL, instead of the category name, /component/virtuemart/ is substituted. On Category pages, language switching works fine.
Module switching language mod_virtuemart_languages
NO is set to Use full category tree for product links in SEO Settings
If YES is set in Use full category tree for product links in SEO Settings then language switching works fine.