That doesn't help. The OS has the pointer at .25" on a 4K 27" monitor. As soon as bridge is launched the pointer drops to about 2mm. I can make bridge a partial sceen window, move back and forth across it. As the mouse starts out .25" on left, drops to 2mm as it passes through the bridge window, and returns to .25" as it exits the bridge window. I'm confident this is adobe dopey responsible, not the OS. Changing background color helps way less than you might think. I'm pretty sure there is an easy fix as there aren't 500 people here saying they have this same problem. I guess I'll keep stumbling around looking for the answer.