Docker Nuget Restore not working getting Found credentials for endpoint and then Unable to load the service index for source

I am having private feed in azure devops and trying to do dotnet restore inside the docker file its not working

I have attached the Dockerfile for reference

FROM mcr.microsoft.com/dotnet/aspnet:6.0-alpine AS base
WORKDIR /app


FROM mcr.microsoft.com/dotnet/sdk:6.0-alpine AS build
WORKDIR /src
COPY Nuget.config /src/
COPY Project/ /src/Project/

WORKDIR "/src/Project"

ARG FEED_ACCESSTOKEN
ENV VSS_NUGET_EXTERNAL_FEED_ENDPOINTS="{"endpointCredentials": [{"endpoint":"https://pkgs.dev.azure.com/OrgName/_packaging/FeedName/nuget/v3/index.json", "username":"docker", "password":"${FEED_ACCESSTOKEN}"}]}"
RUN echo "Environment variables: VSS_NUGET_EXTERNAL_FEED_ENDPOINTS"
RUN echo $VSS_NUGET_EXTERNAL_FEED_ENDPOINTS
RUN apk --no-cache add curl
RUN sh -c "$(curl -fsSL https://aka.ms/install-artifacts-credprovider.sh)"

RUN dotnet restore "Project.csproj" --configfile /src/Nuget.config --verbosity detailed

RUN dotnet build "Project.csproj" -c Release -o /app/build

FROM build AS publish
RUN dotnet publish "Project.csproj" -c Release -o /app/publish /p:UseAppHost=false

FROM base AS final
WORKDIR /app

COPY --from=publish /app/publish .

ENTRYPOINT ["dotnet", "Project.dll"]

I am using azure pipeline with these tasks which works and

- task: NuGetAuthenticate@1
  displayName: 'Authenticate to Artifacts'
  inputs:
    nuGetServiceConnections: 'ServiceName'

- task: DotNetCoreCLI@2
  displayName: 'dotnet Restore'
  condition: ne(variables['CacheRestored'],'true')
  inputs:
      command: 'restore'
      projects: '**/*$(projectName).csproj'
      arguments: '-r win-x64'
      nugetConfigPath: 'nuget.config'
      feedsToUse: config

using the below code to do docker build which is not working

      - task: NuGetAuthenticate@1
        displayName: 'Authenticate to Artifacts'
        inputs:
          nuGetServiceConnections: 'ServiceName'

      - task: Docker@2
        displayName: 'Build image'
        inputs:
          command: 'build' 
          Dockerfile: '**/Dockerfile'
          arguments: '--build-arg FEED_ACCESSTOKEN=$(VSS_NUGET_ACCESSTOKEN)'

I have tried to debug the issue by adding –verbosity detailed to dotnet restore and found that and i am getting the following message in pipeline

[CredentialProvider]VstsBuildTaskServiceEndpointCredentialProvider – IsRetry: True
[CredentialProvider]VstsBuildTaskServiceEndpointCredentialProvider – Found credentials for endpoint https://pkgs.dev.azure.com/OrgName/_packaging/FeedName/nuget/v3/index.json
[CredentialProvider]Sending response: ‘Request’ ‘GetAuthenticationCredentials’. Time elapsed in ms: 0
[CredentialProvider]Time elapsed in milliseconds after sending response ‘Request’ ‘GetAuthenticationCredentials’: 0
1>/src/directory/Project.csproj : error NU1301: Unable to load the service index for source https://pkgs.dev.azure.com/OrgName/_packaging/FeedName/nuget/v3/index.json.

I am not sure why after Found credentials for endpoint i am getting error Unable to load the service index for source