Black Outlines on Render Please Help

For some reason whenever I attempt to render this scene the outline of the character becomes blackened & rough.  It's been attempted on both a backdrop & without a backdrop as well as noise filtering.   So far the only method that has worked to a degree is increasing the resolution to 4K before resizing it back to the 1920 x1080 resolution.   I'm hoping someone might know a permant fix to this solution.