test-element.html
house:{ type: String, notify: true}
A.html
<test-element house="my-house"></test-element>
B.html
<test-element house="{{house}}"></test-element>
<div>{{house}}</div>
Why <div>{{house}}</div>
is not my-house
?
Custom elements are no singletons! Every instance of your Component has its own context. If you want it to behave like a singleton you need to implement redux or use localStorage to store the information