Ranking Up Broken?

I have been rank so fast when I’m rank 72 and I checked the amount of experience I need and now I need 25000. My freind is rank 45 and his total amount of experience he needs to rank up is 25000 to. I can’t tell if it’s my game or its a mistake in the game. I don’t want this to keep happening because it’s like cheating so if anyone know how to fix please tell me.