Can you describe how is the performance worse? Worse overall FPS, more stutters, frame freeze, etc, aside from crashes?
What's your system config?
Windows 10 64
When in mankind divided both in game and the benchmark it is stuttering and the benchmark is 8 fps slower than a single gpu. Doesn’t matter what video settings I choose, vsync on or off. On exclusive fullscreen and crossfire logo appears but is visually slower and stuttering. I’ve left the crossfire on default and tried manually selecting the profile with no change. I’ve checked afterburner and interestingly it looks like each gpu is switching on and off to 100%. Peaks of one card look like they match the troughs of the other. But both are running at full clock speed constantly.