If the keys on the Aerophone Pro AE-30 do not return properly after being pressed, check the following points.
The keys are not moving smoothly
Try fingering the instrument with the power turned off. If any unusual noises or catching sensations occur, the instrument may require repair. Contact your local dealer or Roland support center for details.
The pitch does not change correctly
If the keys are moving correctly but the pitch does not change as expected, an unintended key may be pressed at the same time. See the related Q&A, "Even though my fingering is correct, the pitches are not changing correctly."