Product notifications box disappears when a customer logs in

On my store (ledsales.com.au), which uses the standard Responsive Classic template on 1.5.8, when a customer is not logged in they can see the Product Notifications box just fine (see bottom right of image):

But when they log in, that box disappears for all products:

Tried this on my test accounts and it happens every time.

I had a look and there seems to be no setting that would cause this, and it also happens on the Specials box, but not the Featured or New Products boxes. I changed the sort order of the Product notifications box to move it up the list, and also turned off the Shopping cart box, in case there was a limit to the number of boxes that can be displayed there, but it still didn't fix it.

Couldn't find it as a bug doing a search, any ideas on this would be appreciated...

By default, the system is set up so that users can manage such things from their account page.

https://docs.zen-cart.com/user/products/product_notification/

Thanks, that was the problem, but seems it's off by default and users would have to know to turn it on? That seems an odd choice, should be on by default?