Instant Apps not working on any Pixel XL devices

Question

I've built and published an instant app for my company but it doesn't work on my own Pixel XL, my wife's Pixel XL, my manager's Pixel XL, or his girlfriend's Pixel XL. We see the instant app "speed bump" window (its just blank with spinner) popup very very briefly for under half a second then it offloads to the website. All of our phones properly identify buzzfeed tasty as an instant app in Google search but the behavior is the same. We have tried a number of different known instant apps and none of them work. All devices are running Oreo.

We have verified we are running the latest Play Services. We have toggled instant apps on and off multiple times. Chrome, Play Store, and Play Services for Instant Apps are fully installed and up to date.

For testing I used a Galaxy S7 Edge (Nougat) that worked flawlessly. We have verified that the published instant app shows up for other Galaxy S7 users.

It's a shame that Google's own devices are having the most problems running their own latest and greatest services.

Any idea what the problem could be?