Очень сильно рекомендуем почитать про stacktrace для асинхронных операций в .NET Core 2.1
https://www.ageofascent.com/2018/01/26/stack-trace-for-exceptions-in-dotnet-core-2.1/
https://www.ageofascent.com/2018/01/26/stack-trace-for-exceptions-in-dotnet-core-2.1/
Age of Ascent
Stacktrace improvements in .NET Core 2.1
Intelligible stack traces for async, iterators and Dictionary (key not found)