Tool unions not showing up

So I’m making a gun system (vf9r's Blocky Guns (v0.7) - Roblox)

All of the guns work, except for the Arisaka, the Arisaka doesn’t show up although all of the parts are welded together, and the Kolibri doesn’t show up when it previously did, and the liberator doesn’t show up either, the tools are completely made out of unions except for two parts being the Handle and an Effects part (to raycast)

What is happening, and how do I fix it?

I tried to separate all the parts of the Arisaka but they just dissapeared.
I think the problem is inside the union that has any kind of bug or virus, i dont know exactly which is the problem.
Try to make the gun again in a new baseplate. Probably there it should fix

I tried, it still didn’t work.