XBox One Armour equipment doesn't add up

When equipping Henry with a Milanese plate chaises (MPC), “Leg Plate” total protection is doubled.
In the leg equip box of which there are 4, highlighting the MPC causes two boxes to go yellow, and when “A” equip bottom is pressed, MPCs shown in two boxes equipped and the “Leg Plate” protection doubles the 19, 19, 7 values. It adds 38, 38, 14 to any Leg Plate protection that was already there.
Don’t see a problem with the “Riveted decorated chausses” or "Mail Chausses, although the “Riveted decorated chausses” add one extra point to the “Slash”.
I noticed this before the 1.5 patch, but did not post problem.

Actually, if I unequip all leg protection, and have 0, 0, 0 values, highlighting the MPC shows values of 37, 37, 15, in “Leg Plate” stats, which is not double. Doesn’t add up either way.

Meissen plate chausses and Nuremberg plate chausses do the same as the MPCs.
Haven’t checked other chausses.