Plate Armor Item Weight Bug?

Hi, am I missing something here or is this a bug? I understand that all Tier 3 plate body armors have a base item weight of 100. So with those 29% decrease in item weight on the Knight Armor, how is it still heavier than the Broken Vow’s Mantle? I’m confused!

The display percentage on feather is glitched. It’s not 24% on first, nor 29% on second.

Some display issues on items can be unbugged by sticking it in chest and reloading realm, but no idea if this would work.

Other than that can do your own math to figure out correct percentage.