c++/cli class implementing c++/cli interface - .net-core

Question

I am working in Visual Studio 2022, building a Windows 10 solution with a mixture of native c++, c++/cli, and .NET 6.
I am defining a clr interface in a c++/cli project. The interface methods return types are native pointers and references. The native types are defined in a c++ project. Another c++/cli project should implement the clr interface, however there is a problem with the native types. The error is
Error C2553 'BusinessLogic::IRepository<int,std::shared_ptr<E>> &NlohmannJsonPersistence::JsonRepositoryManager::getProbeRepoRef(void)': overriding virtual function return type differs from 'BusinessLogic::IRepository<int,std::shared_ptr<Domain::Probe> > &NetGateways::IProbeRepository::getProbeRepoRef(void)'
The project with the implementing class, NlohmannJsonPersistence, has a project reference to the project with the interface, NetGateways.
Here is the interface definition in NetGateways:
#pragma once
#include <IRepository.h>
#include <Probe.h>
namespace NetGateways {
public interface class IProbeRepository {
public:
BusinessLogic::IRepository<int, std::shared_ptr<Domain::Probe>>& getProbeRepoRef();
};
}
Here is the implementation in NlohmannJsonPersistance:
#pragma once
#using <NetGateways.dll>
#include <Probe.h>
#include <ProbeFileRepository.h>
#include "NlohmannJSONReaderWriter.h"
namespace NlohmannJsonPersistence {
public ref class JsonRepositoryManager :
public NetGateways::IProbeRepository
{
private:
System::String^ rootDirectory;
Infrastructure::ProbeFileRepository* probeRepo;
public:
JsonRepositoryManager(System::String^ rootDirectory);
~JsonRepositoryManager();
// Inherited via IProbeRepository
virtual BusinessLogic::IRepository<int, std::shared_ptr<Domain::Probe>>& getProbeRepoRef();
};
}
I have tried removing the project reference and importing the interfaces header into NlohmannJsonPersistence but that creates ambiguity in the UI project that depends on NlohmannJsonPersistence and NetGateways. I have also tried removing the #using statement but that produces the same error. Keeping the project reference and including the interface header creates a redifinition error. I think that the issue is that the native Domain::Probe object is compiled into CLI, so when I include the Probe header from the native project, it is incompatible.