[bug] Should OpenTelemetry.Exporter.OpenTelemetryProtocol version 1.12.0 work with OTLP GRPC on .net 9?

[arisewanggithub]

Package

OpenTelemetry.Exporter.OpenTelemetryProtocol

Package Version

Package Name	Version
OpenTelemetry.Api	1.8.0
OpenTelemetry	1.12.0

Runtime Version

net9.0

Description

When upgrade OpenTelemetry.Exporter.OpenTelemetryProtocol to 1.12.0, it breaks metrics with OTLP GRPC. I know this is expected with .net framework and .netstandard 2.0. But we are using .net 9. It also breaks. Is this also expected and we should change to OTLP HTTP Protobuf?

Steps to Reproduce

upgrade OpenTelemetry.Exporter.OpenTelemetryProtocol to 1.12.0

Expected Result

OTLP GRPC should continue to work in .net 9

Actual Result

It breaks

Additional Context

No response

[rajkumar-rangaraj]

No, it should not have any impact with .NET 9. Could you share a minimal repro?

[egg-r]

We upgraded to .NET 9 and latest 1.12.0 release. Afterwards gRPC is no longer working and seems to fail silently.

Is this maybe related to #6280 ? which hasn't been released yet.