It seems that traits that add toughness (shown as green number) don’t work without a food or wvw bloodlust.
Traits that are bugged:
Juggernaut
Dark Armor
i believe there is more but couldn’t find more for now.
From the Juggernaut wiki you linked: “The armor bonus is not always visible, but the incoming damage is decreased correctly.” So the toughness is there, but the numbers just don’t show it.
As for the other, no idea.
They are added, and this has been confirmed in testing with many traits, including Dark Armor. You get the added toughness.
Not affiliated with ArenaNet or NCSOFT. No support is provided.
All assets, page layout, visual style belong to ArenaNet and are used solely to replicate the original design and preserve the original look and feel.
Contact /u/e-scrape-artist on reddit if you encounter a bug.