Ok, a few things to confirm here. Where are you checking that no protecion is gained? When you preview equipping the mod, it should show you a screen afterwards with all your stats that has it highlighted in green what changes will occur when you confirm them.
It will show you right when you equip the mod how much protection it will give you. Afterwards you have to hit confirm to finalize your changes otherwise they will never be visible from the regular character panel, or in combat as the mod will not actually be equipped.
