DDJ-RX is not gonna work

Hi there,

i just got my DDJ-RX controller but it just doesnt want to function.

My system definitely got enough power to run the software. (Win 10)
I got the latest drivers and firmware.

When i connect the DDJ-RX to my PC, start rekordbox and wanna play a track e.g. in channel 1 there will e perfect volume on the channel LED-screen but no sound in master. Also the channel starts to lagg REALLY hard. The song plays that slow that second of the song takes about 15 seconds to play whileCPU usage is on a low level.
When trying to activate a non-ASIO driver the track is playing perfectly but i got no controls via jogwheel (and no sound, of course). 
Another thing that also may be important is that when starting rekordbox, after a few seconds in the bottom line it says that my DDJ-RX is disconnectedwhile the lights are still on and it "works" as I decribed above (gain etc are working). 
i got the channel 1 input on "DDJ-RX-ASIO: CH 1/2".

I was looking for a solution for 2 hours now, but made ZERO progress. 
As I said...latest drivers, firmware, USB from PC-USB to DDJ-RX, cinch-cable from master out 2 to my sound system. The manual won't help either.
Please help...