There's a bug that can be triggered by pausing the game and selecting "Retry" right before an attack that would finish the battle hits. As the battle starts over, the victory screen appears but you're still able to fight. Selecting "Retry" removes the victory screen and you still keep the exp earned.
While it doesn't seem to cause any issues, this allows to farm exp in the same battle indefinitely by repeating the process.
Losing during this process maintains the accumulated exp, and "Back to world" resets it back to normal.
By performing this bug and select "Main Menu" instead, then pressing A to bring up the options, the cursor will disappears shortly after, causing a soflock in the Main Menu and needing to force close the game.
Here are 2 videos showcasing both instances of the bug:
