Yeah I’m still unable to reproduce this bug, I’ve tried filing ingots and sawing rods. What recipe are you using? It might be the mod version you are using as I’m on one higher than you, or it could be something else you have installed.
As for having no incentive to play I also know of another duplication bug. If I press T and then press \give player {item} {amount} I can get unlimited amounts of material for free! It really makes me lose incentive to play the game. If I don’t do that however, then I can play the game just fine. Maybe you can also try not using the bug?