Minecraft xbox diamond sword on anvil?

I have two diamond swords. One has smite 5 and looting 3 and the other has knock back and fire aspect level 2 and sharpness 3. They both has under a full bar of health by they can't be made into one at the anvil. Why!

Try reloading a save or breaking and replaceing the work bench or droping the swords and picking it up if that does not help i don't know i've neve had that happen before