I love the concept of your mod. I started a new game and was trying to design neat rectangles of ore; but while the new patches of ore look good, when I try to mine them, even by hand, I get no (zero) ore? What might I be doing wrong?

What mods are you using?
I haven't encountered anything that would prevent mining once it's printed back down, because it places down the exact same item

Had the same Issue, I had "Infinite Resources" by sonaxaton enabled. I disabled it, loaded the world, saved and re-enabled, and it now works (It worked after disabling the mod)