No Expo network access in emulator/simulator

I’ve got an expo app running in Expo Developer Tools on a PC. I have the Expo app installed on an Android phone and tablet, and access the app over wifi. Everything works great. But when I run the app using the Android emulator or iOS simulator, there is no network access and logins to firebase auth fail. Both simulators have network access in general, and can load pages via their web browsers, and load the app into the Expo app over the network. But once the app is open, the app has no internet access. Any idea what may be the case?

The firebase message is: A network error (such as timeout, interrupted connection or unreachable host) has occurred.

Fails 100% of the time in the simulators, works 100% of the time on the physical android devices.