FE Gun Kit glitches every time I equip a different gun

So, I am currently making my first FPS game on Roblox, and it was going pretty smoothly until I ran into a problem.

I use the FE Gun Kit in my game, and I followed Call Of Bloxia’s tutorial on YouTube.

I created two guns in my game (both with different animations and everything), but every time I equip one gun and switch to the other, the other gun glitches. Then, when I try to switch back, the first gun glitches.

Any help?