[Bug] sshx doesn't work on certain CLI apps

[xtonyjiang]

When running commands like flyctl apps create or gh auth login (after pressing enter a few times), sshx gets stuck and I can't even ctrl+c out of the command. This works for me in my normal terminal though.

[xtonyjiang]

Interesting, seems like if I run these commands in tmux it works fine.

[ekzhang]

It might be related to #60