Hi, @carpedn. When did you make the HAR file? I ask because I see the following headers for the path
cache-control public, max-age=0, must-revalidate
content-type text/html; charset=UTF-8
date Wed, 05 May 2021 01:34:32 GMT
This response occurred on May 5th, 2021. This was over a month ago. If you just made this HAR records now (and not back on May 5th) this is strongly suggests that a service worker is the source of the data.
In addition, there is no IP address for that response. As it would be impossible for Netlify to reply without an IP address, this further supports that the issue is completely caused by the local browser and not by Netlify. Again, service worker is the most common reason why a browser isn’t actually making an HTTP request to the server.
If there are other questions about this, please let us know.
EDIT (two edits): The only solution for this is in the support guide - which is to manually unregister the service worker in the end user’s browser. Also, we’ve seen Safari return 200s for locally cached content even though the cache-control headers say
public, max-age=0, must-revalidate. This is Safari not following HTTP standards and a bug in Safari itself.