With one bass plugged into Input A and nothing in Input B, you should be able to switch between the Bank A presets and the three Bank B presets using the rightmost foot switch. Even though your bass is in A and the selected bank is B, you should still hear your bass. See at 10:08 here:
If that isn't working for you, you might have a bad jack at Input B. You could try inserting and removing a jack in Input B a few times and see if Input A works the way it's supposed to. I haven't had my Deluxe for a while now, though, so unfortunately that's all I can offer.
If that isn't working for you, you might have a bad jack at Input B. You could try inserting and removing a jack in Input B a few times and see if Input A works the way it's supposed to. I haven't had my Deluxe for a while now, though, so unfortunately that's all I can offer.