I am very mush struggling with this
Putting everything else to one side just focusing on "equipping Armor".
Firstly
"Your Armor shouldn't be part of the "Equippable" category. The Equippable Category is meant of Equippable items that use the integration with UCC. Feel free to rename it to WeaponEquippable and have another category called "WeaponEquippable"." I assume you just meant Armor to differentiate between the two of them. that's fine, but really was not clear before and needs to be highlighted for others.
Secondly,
My guess is that you can't see the item being equipped in your equipment UI because you haven't set the correct Collection ID (the collection name) in the Equipment UI (aka ItemSlotCollectionView). You need to specify what collection your UI is monitoring.
are you referring to this ? They work for Weapons, but not the Armor, and I don't know why, but both look like they are setup correctly.
It worked previously when I had just the one collection, but splitting them lead to this issue occurring
Thirdly -
The guidance above said to create a New Item action set with the "Move To Collection Item Action" for Equipping, which I have done here.
I don't see the issue here with the Armour purpose, they are both set to "None"