My front pass side does that as well. I grease the **** out of the sliders and i checked them again a few days later and they were almost seized in. I regreased it again. It seems to be getting too hot i guess. I just replaced the wheel bearing as well. But i know I messed up the install of it. The caliper may be on its way out.
Is your set screw broken? I think mine snapped off. Maybe it's holding the rotor off alignment a bit.