When you connect to a remote PC that is currently in use (e.g., a shared office computer), Zank Remote PC automatically activates "Privacy Mode," which blanks the remote screen and disables the remote keyboard/mouse. The person sitting at the physical PC sees only a lock screen; they cannot see what you are doing on their machine.
Sound isn't playing from the remote PC to my local device. Fix: Ensure "Audio Streaming" is enabled in the connection bar (the speaker icon). On Windows, you may need to set Zank as the default playback device temporarily.