Unmount react component when WpBlock is disconnected

src/gutenberg-packages/frontend.js

@@ -1,6 +1,7 @@
 import { Consumer, createProvider } from './react-context';
 import { createGlobal, matcherFromSource } from './utils';
 import { EnvContext, hydrate } from './wordpress-element';
+import { unmountComponentAtNode } from 'react-dom';
 
 const blockTypes = createGlobal('wpBlockTypes', new Map());
 
@@ -179,6 +180,11 @@ class WpBlock extends HTMLElement {
 			}
 		});
 	}
+
+	disconnectedCallback() {
+		// Unmount the React component, running callbacks and cleaning up its state.
+		unmountComponentAtNode(this);
+	}
 }
 
 // We need to wrap the element registration code in a conditional for the same