Solved! I overlooked something.
Thank you. But with this solution with every update of the theme I would have to change the functions.php.
So I’ll stick to the shop page without sidebar as shown on the demo site. On the demo site there are no widgets appearing on the product page. On my test product page there are two widgets appearing which should have been appearing in the footer. How do I get rid of these widgets on the product page? Ik would like the product page to look as shown on your demo site.