I just bought a used Line 6 Flextone Duo a couple months ago and it has an issue where the presets will not allow me to save, or adjust them. Ill press save and select a channel but it will just switch to that channel instead of saving. I've tried resetting the presets, I've tried pressing them randomly while trying to save on them, I've used manual mode to create the tone and switching after pressing save. I don't know what to do, and I hope I didn't just waste my money on a lemon of an amp. (also has issues with the compressor sounding like its moving all over the place, and its randomly changing the tone while playing. It will be more clear one second, but then sound muffled, then moves around like that)