Unmanaged exports library not working for c# http requests

Question

I wrote a c# dll with some functions that make requests using the inbuit httpclient from the System.Net package. That dll is called from within a Delphi program, the functions are exposed via the UnmanagedExports nuget package. Everything used to work, however a few months I started to get a weird exception.

Basic exported functions work as expected, the problem occurs when httpclient's sendAsync method is called. Program execution stops and I get E0434352 External Exception. Nothing in the projects has changed, the code looks exactly how it did in the last working version, even versions compiled a year ago that were fully operational stopped working. I'm using net4.7.2, visual studio 2019.

Example of a working function:

public static int Add(int a, int b)
{
      return a+b;
}

Example of a non working function:

public static int Add(int a, int b)
{
     var task = Task.Run(() => client.GetStringAsync("https://random-data-api.com/api/v2/cannabis"));
     task.Wait();
     return a+b;
}

In this function execution stops on the task.Wait() line.

Trying to solve the issue i wrote a simple c++ wrapper to bypass the UnmanagedExports package using CLR.

That's how the wrapper looks. Works correctly for basic functions.

#pragma once

using namespace System;
using namespace CSharpNamespace;

namespace TestCPlusPlus {

    public ref class ManagedCPlusPlus
    {
    public:
        int Add(int a, int b)
        {
            CSharpClass^ c = gcnew CSharpClass();
            int result = c->Add(a, b);
            return result;
        }
    };
}

__declspec(dllexport) int Add(int a, int b)
{
    TestCPlusPlus::ManagedCPlusPlus MCPP;
    return MCPP.Add(a, b);      
}

That unfortunately changed nothing, behaviour is the same.

What could be the cause? How do I go about solving the issue?