Could you give some examples of the bugged hats/helms/hoods? I have tried quite a lot of them but can't seem to get the same issue as you.
It might be your settings, or even the client in general. You could try re-installing the game, by using the uninstaller: https://emps-world.net/uninstall

Rewrote major parts of the map loader and cache downloader. If the issue persists in the future, please open another bug report topic. Thank you.