At the higher levels (I am at 55 currently too), I only notice a significant shift in the XP bar when getting experience from the Colosseum.
It is adding your experience, just you will not notice a change because the change will be so insignificant. Leveling a dragon to level 20 will give you about half a bar.
Bane Cane wrote: At the higher levels (I am at 55 currently too), I only notice a significant shift in the XP bar when getting experience from the Colosseum.
Yep and see the page you made a discussion on: Leveling Rewards.