I was making dragonbane bars, but I had to do so manually (old preupdate style) as both the tuned ore and bars have been overlooked, and I got a extra bar, only since it doesn't go into the metal bank, it simply vanished. (wasn't in normal bank or on floor)
all the older bane ores and bars can't be put into the bank, can't be used from bank, and the new extra bar random simply deletes the bar.
also, a bit of a side note, obsidian shards and bars can't go into the metal bank as well.
Dragonbane ore and bars not going in the metal bank is intended. It only stores "core metal" (e.g. it doesn't store granite or sandstone either).
If you want to make ammo, you do it the "old way" which still requires ROTM. This has intentionally not been changed.
If you want to make melee weapons, you do it the "new way" where you make the weapon first, then upgrade it, then tune it.
Are you saying that when you smelted dragonbane bars, you got a double smelting proc ("an extra bar") but you didn't actually receive the extra bar? That sounds like a bug (you shouldn't get extra bars at all).