2FA prompt is not visible

[msakrejda]

If I hit an endpoint that requires 2FA, the CLI does prompt me, but the prompt is hidden:

maciek@mothra:~$ h api get /addons/postgresql-fitted-99834/addon-attachments
GET api.heroku.com/addons/postgresql-fitted-99834/addon-attachments... ⣷

At this point, the "waiting" spinner keeps spinning indefinitely. If I press my Yubikey, the 2FA code is passed along to the API and the call completes, but it's not at all clear that this is what I have to do.