I think there's a typo in the Apparel_Various.xml? Was investigating why the Heavy Plate Armor did not fall into the Apparel > Armor category, and upon adding the bolded word into the code

<thingCategories>
<li>ApparelArmor</li>
</thingCategories>

I got an error, and the armor disappeared from the menu. Then, I found an F-shaped character at the end of the </description>, removed it, and it worked. I am on a Mac using TextEdit because broken PC, so maybe it was me being an oaf, but here's to making sure.