UE5.0.3 VirtualShadowMap gets wrong result after disabling shader optimize

[anonymous_user_efc56e8b1 (anonymous_user_efc56e8b)]

As the title, running UE5.0.3 with DX11 and Video Card is Nvidia GTX 1070 and using the following Console Var Config:

r.Shaders.Optimize=0
r.Shadow.Virtual.Enable=1
r.Shadow.Virtual.NonNaniteVSM=1
r.Nanite.RequireDX12=0
// disable SMRT
r.Shadow.Virtual.SMRT.RayCountDirectional=0
r.Shadow.Virtual.SMRT.SamplesPerRayDirectional=0
r.Shadow.Virtual.SMRT.RayCountLocal=0
r.Shadow.Virtual.SMRT.SamplesPerRayLocal=0
// disbale contact shadow
r.Shadow.Virtual.ContactShadowLength=0

then, the shadow maps are disappeared.

The right result with config:

r.Shaders.Optimize=1
r.Shadow.Virtual.Enable=1
r.Shadow.Virtual.NonNaniteVSM=1
r.Nanite.RequireDX12=0
// disable SMRT
r.Shadow.Virtual.SMRT.RayCountDirectional=0
r.Shadow.Virtual.SMRT.SamplesPerRayDirectional=0
r.Shadow.Virtual.SMRT.RayCountLocal=0
r.Shadow.Virtual.SMRT.SamplesPerRayLocal=0
// disbale contact shadow
r.Shadow.Virtual.ContactShadowLength=0

[anonymous_user_efc56e8b1 (anonymous_user_efc56e8b)]

It seems that something depends on optimize:

// Need to force optimization for driver injection to work correctly.
// https://developer.nvidia.com/unlocking-gpu-intrinsics-hlsl
// https://gpuopen.com/gcn-shader-extensions-for-direct3d-and-vulkan/
OutEnvironment.CompilerFlags.Add(CFLAG_ForceOptimization);