Hi! I'm not really familiar with the pico-emitter library but I'm pretty sure the problem is that you're creating two seperate instances of it.
You're calling const emitter = new Emitter(); in both components, resulting in two completely seperate instances of the event bus. So basically you're listening to an event that happens on the other instance.
The solution would probably be to create a seperate file that initiates the emitter once (maybe call it eventbus.js or something similar) and exports the instance.
import Emitter from 'pico-emitter';
export default new Emitter();
Then in all of your components, import your own file instead of the library. Like this you will always have a single emitter instance throughout all components.
import emitter from '../eventbus';
emitter.emit(...)
emitter.on(...)
All code is untested, but I hope this helps ;)