i can record but my playback doesnt play the sound, i can clearly see the sound waves being recorded, any advice?
It's the game's biggest bug at the moment. From what I can tell so far, the Record effect on the player microphone doesn't work when using 3rd party audio software in Windows, although it could be more than that.
The spectrogram and live mic don't use the Record effect, so they still work, but the Record effect is responsible for your audio playback and saving your performance.