Ok, I assume the 1-ingot blunt bug and the short blades changing material bug are related, but I've been trying to figure out the short blade one in sandbox mode. It's weird.
The problem: When attempting to make short blades, they take the material of the last thing you crafted. If you make a large tin blade, then a short copper blade, the short copper blade turns into a short tin blade.
However, this only happens if the anvil slot you're using to make the short blade has been previously used to make something. If that slot has been used at least once to craft anything at all, all short blades made in that slot will take on the material of the last thing you crafted. Just placing an ingot in the slot and taking it out doesn't affect it, so the bug must happen during the actual crafting process/item creation.
I tested this by ordering two ingots of every metal except titanium, of which I ordered one. I used the left and middle anvil slots to make regular blades and one hand hammers with all of the materials except titanium, then tried to make a titanium short blade using the right anvil slot and I correctly received a titanium short blade.
To make sure, I took three adelite ingots and tried to make adelite short blades in all three slots (from left to right,) and they all came out as titanium short blades.
So I guess the problem is with the anvil slots themselves? On first use, they correctly take the material from the ingot given to them, regardless of what you're trying to make. From then on, however, if they're used to craft a short blade, they ignore the ingot's material and instead use the last material used to craft something.
Aha! I think I just figured out part of the problem! As I wrote that, I thought that each slot might be holding on to the last material used, and that it was going by majority vote. I tried putting two iron bars and one adelite bar on the anvil, started hammering, and got an iron large blade. (It doesn't matter if you hammer the lone ingot, you seem to always get whichever material has the majority.)
Ok...next I tried making regular blades, with two different materials making up the same blade. I was trying to find a pattern to see which material was being chosen, and the bug temporarily fixed itself. I couldn't craft with more than one material and short blades were coming out correctly. Then, after I used the three materials I had on hand, I went to test the rest of the materials to see if I could make short blades with them, and it was broken again. Now I can combine some materials, but not others, and I have no idea what the determining factor is.
I hope I made at least a little sense here. I also hope that this post helps to fix this bug, 'cause I've been doing this for like an hour, and I'm not sure I can figure anything else out without letting my brain cool off. And I'd like for my effort to not be in vain >.<
Good luck, Dasius, and Godspeed!