I doubt there's that much you can do, other than experimenting with the mods you have installed (it's always possible that a mod has strange side effects), or loading a save game before crafting the sword and try again.
It's also possible that the game is struggling at level 100 in NG+. You could also see if there's a mod somewhere that can adjust the damage values (I've always avoided mods so I don't know if there's one).
CDPR is focussing on Cyberpunk and Gwent at the moment, so a patch seems unlikely at this point.