There are several likely causes for this behavior:1) Patches are being set on the controller or module, NOT in Pro Tools program windows. 2) Two MIDI tracks are assigned to the same device and also share the same MIDI channel.3) Program change information is written into the MIDI track data. Set track view to program change and verify there are no program changes written. If there is no visible patch change information and the patches continue to change, try selecting the entire program change playlist for the track and cutting. (Command - X)