Download and Upload Document from C# to AWS HTTP calls take long time

Please share the code you are using to upload or download the document.

Few questions that would help to figure out the issue here:

Is it simply taking time while using C# code, or does it also take time when using other methods? How large are the objects you are attempting to download or upload to S3? Do you make use of Multipart upload requests?

Which AWS service are you using? Please share sample code as well to help debug. In general, follow Microsoft recommended best practices for .NET - https://learn.microsoft.com/en-us/dotnet/fundamentals/networking/http/httpclient-guidelines