This isn’t a bug because every cosmetic is designed to fit the default models since that is their point of reference. That & the cosmetics have different origin points, meaning a model that’s completely different from the defaults can’t be expected to fit everything (at least without per-item offsets which should be a thing!)
Default vs my Niko Model
Aside from that, myself & many others do agree that a separate offset for face items (not glasses items) would be nice.