Pass namespace as a variable to mapFields

[rsf123]

I'm trying to pass the namespace to mapFields as a variable rather than a hardcoded element.
So when I define my component, I pass it a property that defines which namespace in the Vuex store to map fields against. However, it keeps giving me a type error on an undefined property.

My code looks similar to this:
props: ['ns'], computed: { ...mapFields(this.ns,['fieldname','fieldname2'] }

If I explicitly provide the namespace, then everything is working.. Is there a way to pass namespace as a variable?

It LOOKS like the component is mapping the fields from the store before it gets the values of the properties.