We reported this error 2 years ago aprox.
We have created a portfolio based on categories (Nature, Ocean, City)
We have created a menu item for each category (Nature, Ocean, City).
We have published 1 module for each category.
The problem is in the modules, the items should link to respective menu items.
Example:
In the module for the city category there is an element called Lima; Your correct link must be city/item/ID-lima, but instead you have a wrong link nature/Item/ID-lima
In summary, any element of the portfolio links to the first menu item of type com_spsimpleportfolio. This should be fixed soon.