DAW sends stereo - UR242 recieves "mono"


I have been having this problem for ages now:
Whenever I want to use the headphone output of my UR 242 to listen to my DAW (Ableton), I never have a left-right seperation. I know direct monitoring is mono, but this is not direct monitoring, right? I am sending a left only track to the UR 242 and what I get is the same signal on both channels in the dspMix. I was trying everything I could think about, checking the Output configuration, I downloaded the new Update, tried different pannings etc. But always the same result. I attached a screenshot of it. When I turn the pan knob inside the dspMix, I can pan it to either left or right, but the input signal should be panned already. I tried different headphones, but obviously it didn’t even matter, because the signal from Ableton somehow is turned to mono on its way anyway.
Hopefully somebody can help me.
best wishes,
Bildschirmfoto 2017-05-23 um 01.56.56.png