We have tested this on our own installations of Rapido and it works as expected. You can check it out here http://rapidodemo.dynamicweb-cms.com using DemoUser/DemoUser login.
I can see there is a number of customisations on this solution and also a number of additional product catalog pages and also changes to the product index and query. It might be related to one of those modifications.
I guess you have to start debugging to see what happens