Sometimes (high wing) planes exhibit a yaw away from the roll their ailerons are trying to provide. It results from the outside wing having more drag than the inside wing. It's caused by the inside wing having less drag than the outside wing.... chuckle...... yeah.......

One of the visual clues happens because the yaw can make it look to people on the ground like the nose is up and the tail is down.

Differential aileron is often the cure.