How come my model disappears when unanchored after being welded? [SOLVED]

Hi. So I'm creating a vehicle and I have to have PGSPhyiscsSolverEnabled disabled for my project. Now here is the problem. I have narrowed it down to the weld script. For some reason, after it's done welding it unachore's the whole model. In this case a vehicle. But for some reason right after it's unanchored it disappears from the workspace. When PGSPhyiscsSolverEnabled is enabled this is not the case. So what am I doing wrong? Here is the weld script.

function weld()
	local parts,last = {}
	local function scan(parent)
		for _,v in pairs(parent:GetChildren()) do
			if (v:IsA("BasePart")) then
				if (last) then
					local w = Instance.new("Weld")
					w.Name = ("%s_Weld"):format(v.Name)
					w.Part0,w.Part1 = last,v
					w.C0 = last.CFrame:inverse()
					w.C1 = v.CFrame:inverse()
					w.Parent = last
				end
				last = v
				table.insert(parts,v)
			end
			scan(v)
		end
	end
	scan(script.Parent)
	for _,v in pairs(parts) do
		v.Anchored = false
	end
end

weld()
script:Remove()

I fixed the vehicle. It turns out it was not the script but a BodyAngularVelocity object in the vehicle seat. It turns out the P for it was so large that it got the Roblox engine confused and just made it disappear.