C# Dev Kit doesn't pick up transitive package references

I'm trying to debug my .NET Core console app in VS Code. I have two projects: console app and class library. My class library project contains package references to Pomelo.EntityFrameworkCore.MySql which has Microsoft.EntityFrameworkCore as a transitive package. My startup project has a using directive for the latter, however the C# Dev Kit extension doesn't seem to pick this causing build errors, meanwhile the project builds just fine using the dotnet CLI.

How can I fix this without adding a package reference to the .csproj of the startup project?