When running a command like firebase use --add that hits the server, you may receive a timeout error like this:
Error: Server Error. connect ETIMEDOUT 104.197.85.31:443
If so, install the latest version of the CLI, log out, and log back in using these commands:
npm install -g firebase-tools
firebase logout
firebase login
This fix did not work for me. I still got a timeout even after reinstalling, logging out, and logging back in. I tried disconnecting from the VPN and disabling Pihole. No luck,