runtime: I can't build main branch because of ssl issue with the restore

Description

I can’t build main branch from this repo, as the restore stage fails with various SSL errors:

C:\code\runtime\.dotnet\sdk\6.0.100-preview.2.21155.3\NuGet.targets(131,5): error : Unable to load the service index for source https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-public/nuget/v3/index.json. [C:\Users\rober\.nuget\packages\microsoft.dotnet.arcade.sdk\6.0.0-beta.21222.1\tools\Tools.proj]
C:\code\runtime\.dotnet\sdk\6.0.100-preview.2.21155.3\NuGet.targets(131,5): error :   The SSL connection could not be established, see inner exception. [C:\Users\rober\.nuget\packages\microsoft.dotnet.arcade.sdk\6.0.0-beta.21222.1\tools\Tools.proj]
C:\code\runtime\.dotnet\sdk\6.0.100-preview.2.21155.3\NuGet.targets(131,5): error :   Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.. [C:\Users\rober\.nuget\packages\microsoft.dotnet.arcade.sdk\6.0.0-beta.21222.1\tools\Tools.proj]
C:\code\runtime\.dotnet\sdk\6.0.100-preview.2.21155.3\NuGet.targets(131,5): error :   An existing connection was forcibly closed by the remote host. [C:\Users\rober\.nuget\packages\microsoft.dotnet.arcade.sdk\6.0.0-beta.21222.1\tools\Tools.proj]

I the error messages is not always the sames, so it does look like a network issue, but could conceivably be something I’m doing wrong too.

Configuration

• Which version of .NET is the code running on?

>dotnet --list-sdks
C:\code\runtime\.dotnet
6.0.100-preview.2.21155.3 [C:\code\runtime\.dotnet\sdk]

c:\code
>dotnet --list-sdks
2.1.815 [C:\Program Files\dotnet\sdk]
2.2.207 [C:\Program Files\dotnet\sdk]
3.0.103 [C:\Program Files\dotnet\sdk]
3.1.114 [C:\Program Files\dotnet\sdk]
5.0.101 [C:\Program Files\dotnet\sdk]

• What OS and version, and what distro if applicable?

Windows 10 -10.0.19042 Build 19042

• What is the architecture (x64, x86, ARM, ARM64)?

x64

Regression?

This is the first time I’ve attempted to build on this laptop<

Other information

I noticed it looks similar to this issue: https://github.com/dotnet/runtime/issues/52053 , but I don’t think it’s the same issue as the download of the initial sdk seems to work okay.