I know this is an old topic, but I have the same issue once I install the Brotherhood of Shadow mod. PMHA05 has that same hair glitch, and I figured out it was the appearance.2d a file. Since replacing it with a pre-BOS appearance file, the glitch is gone. After looking online for more explanations on manipulating the appearance file, I figured out that you need the KOTOR tool. Tried the above method, but that doesn't seem to be the issue since the envmap for B model type is set to default. Again, if anyone could recommend a fix or point me in the right direction, I'd appreciate it. Because the other method mentioned by DarthParametric didn't work for me either.
Again, thanks for any recommendations. I appreciate any replies.