Android Studio debugger console displays "Failed to connect port"

Try set Debugger type to "Java Only"

You can follow this way:

Run -> Edit Configuration -> Android App -> Your app module -> debugger -> set "Java Only"

It's caused by broken Android SDK Platform-Tools 29.0.3

To solve this issue you should download platform tools 29.0.2 from (mac, win, linux). Extract it and replace platform tools inside Android SDK.

UPD: This issue has been hotfixed with platform-tools 29.0.4: https://issuetracker.google.com/140369526 Now you can update to the latest version, instead of a downgrade.