Expo, что -то пошло не так.

What solved this for me was simply changing the connection from LAN to Tunnel. 
When you start an expo app, 
a browser window will open with a URL like http://localhost:19002/. 
Along the left side is a Connection option set to LAN by default. 
Changing it to Tunnel before scanning the QR code with the expo app solved it.
Silly Skunk