Doesn't work master out in UR44

Steinberg Hardware UR Series
1

Hello

I’m using UR44 with Ableton Live. When i rout master channel in my DAW to 5/6 output there is only REV-X signal in my mix and there is no indications of DAW signal in dspMixFX panel. This thing appears even when i turn off REV-X send from mix1.

Thanks