you did a minor mistake in your call.

From your picture I can gather, that you are calling the function with dispatch('tasks/fbreadData), but fbreadData({commit}) seems to be within your getters from store-tasks.js

You can either call it as a getter.

handleAuthChange({commit, rootGetters}) {
  // ...
  rootGetters['tasks/fbreadData'];

} 

or you can reposition fbreadData into your actions in store-tasks.js.

I would decide that depending on whether you need to do additional tasks within fbreadData, or you are just returning a value.

Function does Something = Action

Function does nothing but return a value = Getter