If a cloth armor already has a magic bonus of +1, which is often the case on the module, then the perk bonus is smaller, even if those bonuses don't stack.
To be a little more clear;
If you wear a leather armor +1, your AC will be lower than if you're wearing a normal leather armor.
So if you're wearing +1 leather armor, you won't get any kind of ac bonus from the perk.
You'll get an ac bonus, from the perk, that is 1 point lower than if the armor was not +1.
And since they are bonuses of the same type, they do not stack. The result is that your character's AC is lower.
This is a result of the script trying to prevent things like +1 ac bracers (which are now pretty rare, but used to be fairly common back in the day) from adding to regular worn armor. So, you can't wear full plate and get the bonus from the bracers, too. Since the 'Armor of the Wilds' doesn't recognize the +1 on the clothes, but the script does, you end up with -1 ac penalty.
Little bump.
Bumpidoo.
This isn't a bug, you might just be better off applying your +1 armor bonus to an item that lacks that bonus but has much more beneficial properties.
Bump
Ok, it's been over 3 months, bumped many times, still not fixed nor acknowledged.
How can I politely say you guys suck?
Locked.