The experience gained is enough to level up, but still nothing happen, you can see the experience has reached the cap
Have you tried killing a random monster to see if you get any xp? The bug you are referring to usually happens when a low lvl has killed or leeched from a boss which has the exp equivalent to multiple levels. The solution is usually to kill a snail (or any mob) to level up. If that doesn't help, I guess this belongs to another place, i.e. character issues.
