Short Answer – change the name to be unique!
Long Answer – I was creating my own version of the 74HC595 shift register in KiCad and named it exactly that. When adding it to my own library, and using it in my schema, it kept showing me the stock version. So the fix to this was to right-click on the name in the component editor and change it to something else – “MY74HC595” and save. Hey presto! Problem solved 🙂