Problem with DDJ-SX and Update 5.7

Hello
I`m using Rekordbox 5.7 with a DDJ-SX controler
Since updating from 5.6 to 5.7 I got problems in automix mode
If I want a titel in the second player manually the song starts but i hear no sound
I have to move the crossfader for 1mm then the sound is available
Also when I start Rekordbox with connected controller i have to move every regulator that the software recognize the correct position
I found a unistalled version 5.4 on my Laptop, here is working everything fine
newest drivers and controller fimware is installed

Any suggestions