It seems some of the cosmetics that used to be equippable aren't right now. We are looking into the issue. I've written up the Cyberpunk
sparkyphantom958 and the Steampunk Dynamite Arm-band
SnapJackalPop for the devs to fix. I'll keep looking for others, but if you have any other cosmetics that this bug affects, letting me know the specific ones would help me. Thanks!