Then it's either that you didn't empty the "canonical URL" setting of the products you're looking at (but you said that the product didn't have a canonical URL in your first message)
: I have been around the products, categories, menus, modules and configuration to find any reference to canonical URL; where it exists it has been left blank
or you have some caching that you need to clear to see the change
: I gave this a week and worked on two sites, local and server.
Regarding products disapearing from the listing, that has nothing to do with changing the alias of the menu item. So it must come from something like, like for example the products don't have any stock anymore and you've configured the menu item to not display the products out of stock
: the stock is set to "unlimited" and the display setting on menu is set to show.
OKAY FIXED!
In "Modules: mod_hikashop" I had not assigned a menu in "data display". I have now assigned "products listing" as menu and that works
Thanks for assisting in the troubleshooting. Appreciated.