Blur or ghosting issues at the edges of hair or clothing are related to the portrait mode's bokeh effect, which is designed to blur the background and highlight the subject. The edge detection and background blur algorithms used in portrait mode can struggle with fine details, like hair or fabric, resulting in unwanted blur or ghosting effects.
The bokeh effect is continually being refined through system updates. To address these issues, it is recommended to keep your device's system version up to date. Updates include improvements to the image processing algorithms, which can enhance edge detection and reduce blur or ghosting artifacts in portrait photos.