it seems everyone is experiencing the same graphical bug. I remember finding out the core issue of this bug that seemingly is the same one from tacticowl temporary beta. I don't know if this is the same bug. But this is how I solved previously.

It seems that certain weapon mods contain files for built in compatibility with the sheath your sword mod. Somehow, these files are the ones causing the graphical bug in dual wield even if you don't have sheath your sword installed. So what I did is directly delete these files. I go to the 294100 folder. Which is where all the steam mods are located. Used the search function to find all the files by typing "SYS". And delete all files pertaining to sheath your sword compatibility. Specifically, delete both 'sys.dll' and 'sys.patch'

Now its safe to say. Take what I said with a grain of salt. I found out about this being talked about in the original dual wield mod's bug reports i think?

Another note. Some mods have gameplay functions connected to these files. I just found out that if you delete the sys.dll from the pavia mod. Melee pavias will lose their weapons and mechanitor will try to infinitely repair them.