Random loudness on patches

[tedcrop]

I get random loudness increases on different keys. Its very noticeable. There is a pattered but it happens on all the keys.

I can play a pattern and the same keys get louder in the pattern, but I can move it up and down the keyboard so its not just one key.

[AlainHubert]

Have you tried recalibrating the unit ? (Manual+0)

If that doesn't fix the issue, and if the problem shows a pattern, try to notice if that pattern cycles every 6th note. You might have a defective voice card.