There are currently 2 bugs with armoring mods. 1 is if you apply armoring to your armor first, then add skill kit, gadget, or utility it will negate the armoring value back to the default. For example if you add a plasma resistance then add the other mods it will reset the plasma value back to default. The way around this for now is to add armoring AFTER skill kit, gadget, and utility. 2 is when you add armoring after tinkering. For example, if you tinker your armor up by 5 levels then later decide you want to add plasma resistance, it will actually reset the value for that element back to what it was before you tinkered. So be sure to add armoring mods AFTER skill kit, gadget, and utility. BUT BEFORE you start tinkering. Cheers