You have to click on the kebab menu next to the result title - you should see a modal popup titled "About this result". Then you either have to expand the "More

You have to click on the kebab menu next to the result title - you should see a modal popup titled "About this result". Then you either have to expand the "More Options" collapsed at the top to see the "Cached" pill, or scroll to the bottom of the modal to see it - it seems like they have 2 versions they're A/B testing. I'm not sure why but it seems like they're really trying to make it hard to find.