From the looks of this search...
https://www.google.com/search?source...sclient=psy-ab
it seems like it could be a somewhat common issue.
Past that, have you tried a factory reset to see if you have the same set of issues afterwards?
Can I reset the controller to the factory default settings?
Yes! To reset the keyboard to factory defaults:
Make sure your computer is powered on.
Power the Keystation Mini 32 by plugging in the USB cable from your computer while simultaneously holding down the Oct/Data "+" and "-" buttons.
Good luck.