google-cloud-dotnet: A running SubscriberClient causes exceptions after a few seconds

Environment details

• OS: doesn’t seem to matter (tested it in Windows 11 as well as in a Ubuntu Docker container)
• .NET version: net7.0
• Package name and version: Google.Cloud.PubSub.V1, Version 3.6.0

Steps to reproduce

I have a Visual Studio solution with the minimal setup, which I would like to add to a GitHub repo, but it seems like GitHub currently experiences some problems, and I can’t create a repository. So here is a zip file: PubSubTestAspNet.zip

1. Download the zip file
2. Extract it
3. Open the solution with Visual Studio
4. Fill the placeholders (<...>)
5. Run it
6. Open the “Output” window

Now wait for about 70 seconds. After that, Visual Studio begins to log occurring exceptions:

Exception thrown: 'System.Threading.Tasks.TaskCanceledException' in System.Private.CoreLib.dll
Exception thrown: 'System.Threading.Tasks.TaskCanceledException' in System.Private.CoreLib.dll
Exception thrown: 'Grpc.Core.RpcException' in Grpc.Net.Client.dll
Exception thrown: 'Grpc.Core.RpcException' in Grpc.Net.Client.dll
Exception thrown: 'System.Threading.Tasks.TaskCanceledException' in System.Private.CoreLib.dll
Exception thrown: 'System.Threading.Tasks.TaskCanceledException' in System.Private.CoreLib.dll
Exception thrown: 'System.Threading.Tasks.TaskCanceledException' in System.Private.CoreLib.dll
Exception thrown: 'System.Threading.Tasks.TaskCanceledException' in System.Private.CoreLib.dll
Exception thrown: 'Grpc.Core.RpcException' in Grpc.Net.Client.dll
Exception thrown: 'Grpc.Core.RpcException' in Grpc.Net.Client.dll
Exception thrown: 'Grpc.Core.RpcException' in Grpc.Net.Client.dll
Exception thrown: 'Grpc.Core.RpcException' in Grpc.Net.Client.dll

It starts slowly, but it’s getting worse with time. Also, the performance degrades the longer the solution is running.

Is this a bug or am I using the library the wrong way?

Thanks!