Why did my Level change when I switched class?

Every class keeps its own Level and its own XP. The Level you see is always the Level of the class you are wearing now.

So a class you have not trained yet starts low. Switching to it does not take anything away from the class you left.

Your old class keeps its Level and its XP while you are away. Wear it again and the Level comes straight back.

Rewards are collected once. When a second class climbs past a Level you have already been paid for, that reward does not pay again.

Learn more: What do I get for levelling up?