These are two issues:
a) we have fixed the “invisible mixer” problem, but the version is yet to be released. However re-opening pretty much always fixes the problem, pls try again. Are you sure you are connected at all? Do all 6 LEDs lit green?
b) for the Performer to hear your voice, the Talkback bus has to be set properly in the Control Room setup (menu Devices/VST Connections/Studio). Also make sure Talkback is enabled and Talkback Dim (also in Control Room Mixer) is not set too low. For the Performer to hear any playback channels, those have to have active Cue Sends to the VST Connect Cue bus which is also controlled in the Control Room Mixer.