Currently if you use the outfit station to create a look with a helmet, the hide helmet option in collections no longer works to remove your helm.
Personally I like to have my character's helmet on some of the time, but other times I hide it (after all, i and others have spent good money on hairstyles and customization, sometimes we want to see our faces). This used to be possible even with costumes but no longer. Now if you want to remove your helmet you have to go back to an outfit station and hide it - and then when you want to put it back, you have to pay gold again to reapply it.
PS4 / NA
M'asad - Khajiit Nightblade - Healer
Pakhet - Khajiit Dragonknight - Tank
Raksha - Khajiit Sorcerer - Stamina DPS
Bastet - Khajiit Templar - Healer
Leonin - Khajiit Warden - Tank