First here are my diagnostics:
During the development of one of my expo projects all of a sudden, I encountered the described error message.
On the local network, I cannot log in to the expo client app on android emulator and a physical device. Also not through the expo-cli
expo login command.
Login out of the expo forums also executes a call to exp.host and thus fails for me.
What might this be? A DNS issue as stated in related issues?
BTW, I created a new blank test project and this issue also occurs!