Removing favorite tags doesn't take effect unless you click outside of the form field before navigating away

[cellio]

https://software.codidact.com/posts/283051

Reproduce steps from an answer there (Firefox):

1. In your preferences, set some favourite tag(s). Make sure you click outside of the favourite tags edit field to make sure the edit field has lost input focus.
   
   (When the edit field is losing input focus, data in the browser's local storage is updated to reflect the current favourite tags from the edit field.)
   
   

2. Navigate to the question list page to verify the highlighting of the favourite tags.
   
   

3. Go back to the preferences, and clear the favourite tags edit field. However, this time DO NOT let the text field lose input focus. Directly and immediately navigate away from the preferences page, for example by clicking directly on the link in the top banner leading to the questions list.
   
   (This time, the local storage is not being updated with the changed favourite tags field content.)
   
   

4. Note how the question lists still highlights the previous favourite tags.
   
   

5. Go back to preferences and check again the emptiness of the favourite tags text field.