We have a custom deployment engine that uses the Service Fabric HTTP client (Microsoft.ServiceFabric.Client.Http) to deploy Service Fabric applications. It runs fine on .NET Framework 4.8, but if we use .NET 6, our second application upload to the Service Fabric image store times out, along with all subsequent uploads from within the same deployment process. The first app upload takes about 15 seconds, and the second times out after 100 seconds (the HTTP default timeout) even though the app content is the same size. It happens every time we run, but if I switch back to .NET Framework 4.8, it works fine (all apps upload within about 15 seconds).
I have tried disabling all of the new socket and IPv6 stuff in my process, but no luck.