Guild Wars 2

Erm i just rolled a new warrior and i realized that, endure pain skill says that you do not take dmg from attacks for 5 secs, however when i used it it only last for 3.. ive tried it multiple times and recorded the times, and it seriously is definitely not 5 secs.. so i was wondering if this is a bug or like a scam to make the skill look better than it actually is…

I believe its a known bug