Unity URP Shader GrabPass vs MultiplePasses

Question

Im working on intersection shader on URP that can recolor (grayscale) intersected area. So i got it working on SRP but when using URP its not working properly. I think its something wrong with GrabPass on URP. And i need help. Thanks)

Shader '''

Shader "Custom/Grayscale" 
{
    Properties
    {
         _Color("Color", Color) = (1,1,1,.2)
         _Blend("Blend", Range(0,1)) = 0.0
    }
    SubShader
    {

        Tags{ "Queue" = "Transparent" "RenderType" = "Transparent" }
      
       
        GrabPass
        {

        }
       
        //stencil pass
        Pass
        {
            Tags { "LightMode" = "SRPDefaultUnlit" }
            Stencil
            {
                Ref 172
                Comp Always
                Pass Replace
                ZFail Zero
            }
            Blend Zero One//Zero One
            Cull Front
            ZTest GEqual
            ZWrite Off
        }

        //color pass
        Pass
        {
            Tags { "LightMode" = "UniversalForward" }
            Blend SrcColor OneMinusSrcAlpha
            Stencil
            {
                Ref 172
                Comp Equal
            }
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"

            float4 _Color;
            float _Blend;
            sampler2D _GrabTexture;

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };
            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
                float4 grabUV : TEXCOORD1;
            };
            v2f vert(appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.grabUV = ComputeGrabScreenPos(o.vertex);
                return o;
            }
            fixed4 frag(v2f i) : SV_Target
            {
                half4 bgColor = tex2Dproj(_GrabTexture, i.grabUV);

                float intensity = bgColor.x * 0.299 + bgColor.y * 0.587 + bgColor.z * 0.114;
                fixed4 bandw = fixed4(intensity, intensity, intensity, 1);
                fixed4 lerped = lerp(bgColor, bandw, _Blend);
                return lerped;
            }
            ENDCG
        }
    }
}

'''

Also added GrabPass render feature

'''

public class GrabPassFeature : ScriptableRendererFeature
{
    [System.Serializable]
    public class Setting
    {
        public string textureName = "_GrabTexture";
        [Range(0, 1)] public float sampleDown = 0.5f;
        public RenderPassEvent passEvent = RenderPassEvent.AfterRenderingPostProcessing;
        public bool useBlitMat = true;
    }
    public Setting settings = new Setting();

    class BlitPass : ScriptableRenderPass
    {
        Setting setting;
        Material BlitMat;
        //RenderTexture rt;
        //RenderTargetIdentifier colorBuffer;

        public BlitPass(Setting setting)
        {
            this.setting = setting;
            BlitMat = new Material(Shader.Find("Hidden/Universal Render Pipeline/Blit"));
        }
   
        public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
        {
            if (renderingData.cameraData.camera.cameraType == CameraType.SceneView)
                return;

            CommandBuffer cmd = CommandBufferPool.Get("Grab " + setting.textureName);

            RenderTextureDescriptor desc = renderingData.cameraData.cameraTargetDescriptor;
            int width = (int)(desc.width * setting.sampleDown);
            int height = (int)(desc.height * setting.sampleDown);

            int textureId = Shader.PropertyToID(setting.textureName);

            cmd.ReleaseTemporaryRT(textureId);
            cmd.GetTemporaryRT(textureId, width, height, 0, FilterMode.Bilinear, RenderTextureFormat.ARGB32);

            if (setting.useBlitMat)
                cmd.Blit(renderingData.cameraData.targetTexture, textureId, BlitMat, 0);
            else
                cmd.Blit(renderingData.cameraData.targetTexture, textureId);

            context.ExecuteCommandBuffer(cmd);

            CommandBufferPool.Release(cmd);
        }
    }

    BlitPass mBlitPass;

    public override void Create()
    {
        mBlitPass = new BlitPass(settings) { renderPassEvent = settings.passEvent };
    }

    public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
    {
        renderer.EnqueuePass(mBlitPass);
    }
}

'''

I got bad skills at shaders, so a bit of explanation would be helpful)