Diablo III, anniversary exp bonus bug?

I have a 0% experience bonus on my level 70 Demon Hunter and my level 56 Crusader.

And yes, I've verified that this is not just a display issue; my heroes gain the same experience killing monsters that they did yesterday.

I would like to know whether this 0% bonus is intended before reporting a bug to reclaim my bonus tomorrow or whatever Blizzard team decide to do.

By the way, if there is a reason explaining why a player could have 0% bonus I would like to know the url of the official page where it is explained.