I seem to having trouble saving amp model parameters changes from one snapshot to the next. For example I have a Fender Twin in the signal chain and for snapshot 1, I set the drive level to 4 and the save the patch. Then switch to snapshot 2 and set the drive level to 8 and save the patch. When I switch back to snapshot 1 the drive level is still at 8. What am I not doing correctly? My goal is to be able to go from clean to a little more dirt.