SIte malfunction problem

[raunhar]

Joomla Version: 3.6.5
VM Version: 3.0.18

URL: http://www.corporate-gifts.net
Problem:
When I click on any Product Type (like Tech Products or some thing else), the products show up.
But when I click on the back button of the browser, it shows up a blank page with the message No Products found.

How to solve that.
I am also using Break Designs Custom Filter on the web site. The Product Type is a Custom Field.

[jenkinhill]

Back arrow worked OK for me, tested with Firefox Chrome & Edge.