dotnet test doesn't recursively search folders for .csproj with wildcards

I want to run all tests in several dotnet core C# test projects.

From the root folder if I run 'dotnet test /*.test.csproj' it will only run the tests one folder down. From the root folder if I run 'dotnet test **//*.test.csproj' it will only run the tests two folders down.

How can I get 'dotnet test' to recursively check all folders for a *.test.csproj project? i.e. run test from both projects above.