Guild Wars 2

After creating 8 enchanted reward boosters I selected the experience booster, once when I was in a pvp match and once out of the pvp match in the Hotm lobby.

The first time I used it in a pvp match it used my item but did not grant me any boost.

The second time I used it in the HotM the time remaining of the booster was 20 minutes instead of the intented 1 hour, although I believe it got buffed to two hours a little while ago.

This got me the first time too. When you use the Enchanted Reward Boost item, the first 2 boosts are ONLY 20 MINUTES, and are noted as such in the description. This is because the first 1 (Exp) boosts XP, WXP, Kill Streak XP, and PVP reward progress (like the NEW XP boosts) and the second 1 boosts MF, Crafting, and gathering (like the NEW Item boosts). The remaining selections allow you a full hour of the OLD boosts that existed before (including the OLD XP boost, but not WXP boost, which has never been available throught the Enchanted Reward Boost).

I imagine this is because it would be a bit absurd to let you trade in inferior old boosts and get the full 2 hour benefit of the new boosts. Also, you CANNOT make the new boosts into Enchanted Reward Boosts, only the old boosts.