Coach is showing assets are missing a cache time but they are definitely present

• Exact how you run (the exact parameters)
  docker run --rm -v "$(pwd)":/sitespeed.io sitespeedio/sitespeed.io:12.10.0 https://www.sainsburys.co.uk/shop/gb/groceries/fruit-veg/all-fruit\?fromMegaNav\=1
• Which version you are using
  12.10.0
• OS (if you use Docker, report the base OS)
  MacOS Catalina 10.15.4

When I'm running the above command and checking the coach output, one of the recommendations it gives states "The page has 276 request(s) that are missing a cache time. Configure a cache time so the browser doesn't need to download them every time. It will save 1.7 MB the next access."

However when I check one of the specific assets (in this example https://www.sainsburys.co.uk/wcsstore7.46hf.15/SainsburysStorefrontAssetStore/css/main.min.css), I can see that it does have a valid Cache-Control response header (Cache-Control: max-age=3600, s-maxage=3600, no-cache="set-cookie").

I can also see that in the waterfall in the report produced by sitespeedio.

I have attached a zipped copy of the run. Please can you take a look and confirm whether this is an actual bug?

Thanks!

www.sainsburys.co.uk.zip

Reproduce the issue with the exact Docker command, sitespeed.io 12.10.0, and the supplied URL, then inspect the Coach output, waterfall, and attached run archive. Done means determining why an asset with the shown Cache-Control header is reported as missing a cache time and correcting the recommendation if it is a bug.