I tried saving it with paint and still no luck. I also removed all my gear to see if that would change it back, it still was default.Try loading the file through a program like paint, and then saving it again as png.
Edit:. Also, pay attention, because some gears that partially shows the head may
place a model of the normal player head, I'm still looking for what is causing the issue
so the only fix at the moment is use a vanity gear that shows the modded head.