Alright. So this is somewhat embarrassing, but I figured it out with BMXTRIX's advice. I had been changing the settings and whatnot, but I guess I was just changing the overall volume and not the Zone 2 volume. I really struggle with this remote and manual. Anyway, when I figured out that I wasn't actually changing Zone 2's volume, I went back and tried again, and of course Zone 2's default volume is muted. So now all is well. Thank you for your help.