No overdubs available after saved the song

I’m on 4.3.0 beta of the Aeros
If I play a song with overdubs I can undo/redo the layers 2X2 Mode
But if I save the song to play it later, there is no overdubs anymore , the track is a whole track
If I undo/redo it’s like a mute/unmute there is no layers on a saved song?

I downgrade to 4.2.4 and is the same . No ovedubs on saved songs in 2X2 mode

Best regards