What should you do if Photoshop leaves a white outline around the subject?

Sometimes, a fine outline of white or a color appears around the subject after remove background photoshop. As Visuals Clipping explains, this can occur if "pixels of the original background are added around the selection edge. The unwanted halo may be minimized by refining the layer mask or by adjusting the selection. Manual masking using masking fluid and paint gives more control in areas where it is hard to paint. It is also helpful to be able to view a subject on both light and dark backgrounds to help identify remaining edge problems.

Read more- https://www.visualsclipping.com/blog/how-to-remove-background-in-photoshop/