Using EnableMatrix with a Y Axis inverted Matrix doesn't seem to work anymore.

[MagentaIris]

64-Bit. If you need more code and context please brick my face for more.

Using an Inverted matrix scale on the Y Axis for View Model Flipping doesn't seem to work anymore?

I'm trying it alongside using render.CullMode(1) to flip a viewmodel (Yes, the viewmodel is a Clientside Model.)

Before rendering it via DrawModel() (Yes it is NoDrawn first)

Here's my creation method:

GAME_VIEWMODEL1 = ClientsideModel( Model(CVM_DefaultModel), RENDERGROUP_OPAQUE )
GAME_VIEWMODEL1:SetPos( POS )
GAME_VIEWMODEL1:SetAngles( ANG )
GAME_VIEWMODEL1:SetNoDraw(true)

Here's my matrix's:

INV_MATRIX = Matrix()
INV_MATRIX:Scale( Vector(1,-1,1) )

NORM_MATRIX = Matrix()
NORM_MATRIX:Scale( Vector(1,1,1) )

Here's my rendering function (VM in this context is GAME_VIEWMODEL1):

if FLIP then
	render.CullMode(1)
	if not VM.FLIP_MODE then
		VM.FLIP_MODE = true
		VM:EnableMatrix("RenderMultiply",INV_MATRIX)
	end
else
	render.CullMode(0)
	if VM.FLIP_MODE then
		VM.FLIP_MODE = false
		VM:EnableMatrix("RenderMultiply",NORM_MATRIX)
	end
end
		
local WEP = OWN:GetActiveWeapon()
			
if WEP and not WEP.WEP_Scoping then		
	VM:DrawModel()			
end
			
render.CullMode(0)

This is where my rendering function is being called from:

function SWEP:PostDrawViewModel( vm, wep, pl )
		
	if CVM_DrawViewModels then
			
		DO_DRAW_DRAWS = true
			
		CVM_DrawViewModels()
		
		DO_DRAW_DRAWS = false
			
	end

end

This does not invert the models scale on the Y axis, it does change the cullmode correctly though.

Trying this on a normal ClientsideModel created using lua_run_cl seems to work fine, But I'm drawing my stuff here inside of PostDrawViewModel() in an active SWEP.

Any ideas why this is being a problem? I've tried disabling a lot of different parts of the code but it never seems to work.