sampling problem with 2k XL

My 2kXL has a weird sampling issue. When I sample mono (L or R) it just works fine. But in stereo the sounds has no low at all and sounds slightly distorted. When I stay in stereo mode but remove L or R it's back to normal.

Anyone an idea?

sounds like some phase issue is happening... are you using some sort of Y cables or is you sample source connected in a weird way?