Auth basic 401 page does not prompt for credentials due to PWA service worker caching
I would suggest processing the response.status value. If it is not 200 (response.ok) then you probably don't want to cache it.
I recommend running responses through some sort of if/else or switch/case logic for scenarios like handling different response status code, content types, routes, etc.
Service worker caching gets complicated the more complex your application is :)