Exp. Gain Malfunction

All of a sudden my Pokemon are only gaining 1 exp. per battle. Is there anyone who has also encountered this, or has any suggestions for fixing it?

In hard mode, once you get to the level cap your pokemon only gain 1 exp. Its so that you can’t overlevel and make the game too easy. If you don’t like this, switch to normal

Once you beat a milestone like a gym leader or cult leader, then the cap raises and you can get exp like normal again.