XDJ-XZ with VDJ 2024 problems - no audio on second channel

Howdy,
I have a problem with XDJ XZ. I updated the firmware recently and it still doesn't recover.

After ~2-3 hours of playing music in VDJ, it cuts the sound from the console, it plays the channel that is already up but the other one no longer has sound, it doesn't even go on channel 3 if I try.
Everything seems functional (VDJ reacts normally, the sound is visible in the program on the meters, the control is OK), but the sound from the XZ is not heard.
I noticed that if I remove the control cable from the laptop and plug it back in, the XZ no longer appears as mapping (I no longer see the shape of the song or the playlist), but it works flawlessly without interruption.

Do you have any idea what I can do to them?

Thank you!
John