If it's a software glitch, then updating and/or initializing could fix the problem. Initializing will erase your presets so you will want to back them up first using Factorlib, found here.
To initialize:
Power up the unit while holding down both the middle footswitch and the encoder button for a few seconds.
If you still have problems you should email support@eventide.com as the unit may have to get repaired.
