Import Pbix File as Service Principal

I have the following settings going

- Tenant Developer Setting is enabled for Service Principal to access Admin APIs

- Service Principal is added as administrator to the workspace

- I am trying to upload a pbix to import as a report + dataset using the following 

                    _ = await client
                        .Imports.PostImportWithFileAsync(
                            powerbiGroupId,
                            stream,
                            reportName,
                            ImportConflictHandlerMode.Overwrite,
                            skipReport: false);

- powerbiGroupId = workspace ID

- stream = stream from the file

- reportName = valid report name to be uploaded

I keep getting 

System.Net.Http: The operation was canceled. System.Net.Http: 
Error while copying content to a stream. System.Net.Sockets: 
Unable to read data from the transport connection: 
The I/O operation has been aborted because of either a thread exit or an application request.. 
The I/O operation has been aborted because of either a thread exit or an application request.

The file is between 1MB - 1.4 MB. How do I check what the underlying issue is. Is there a limit that I am hitting ?