Merging Surfaces for smooth lighting?

I primarily work with poly modeling programs like maya and 3ds max, so Creo is somewhat new to me. My studio uses Creo Elements/Direct Modeling to process and convert native CAD data to stp format. I'm running into a problem where two particular surfaces meet on this model. The seam is not smooth, and this affects lighting downstream with our render engine. I can't figure out how to join/weld these surfaces so that light bends around the curve smoothly with no hard edge. I've attempted using the merge tool, and I've also tried modifying the blend, but I can't fix it. I'm assuming this should be a simple operation, but I'm at a loss here. Does anyone have any advice? Thank you!