I have a favorite connection to my atlas free tier. For some reason, it includes the password as "undefined" which results in the connection timing out (rather than failing or prompting for passwd). I've attached a screenshot.

Here's the URL that was auto-populated.

mongodb://dan:undefined@surflog-shard-00-00-u9fko.mongodb.net:27017/admin?authSource=admin&replicaSet=surflog&readPreference=primary&appname=MongoDB%20Compass%20Beta&ssl=true

If I go to the "Fill in connection fields individually" screen it will render as "******"

If I fill in the password correctly, then toggle back to the shortcut screen, the password is correct.