Browser not setting cookies with SameSite=None when interacting with Web API

When developing a React web application that interacts with a server via a Web API, I encountered an issue where the browser does not store cookies with the SameSite=None attribute.

My React application, running at https://localhost:3000, sends POST requests to an API server at https://localhost:7000. The server responds with a Set-Cookie header, attempting to set a cookie with the attributes SameSite=None; Secure. However, despite the presence of this header in the response, the browser does not store the cookie, and subsequent requests lack the necessary authentication data.

If I use the same domain, the cookies are stored.

I tried:

fetch('https://localhost:7000/api/login', {
  method: 'POST',
  credentials: 'include',
  headers: {
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({ username: 'user', password: 'password' })
})
  .then(response => {
    // Handle response
  });

aspnet:

//Cookies
cookies.Append("AccessToken", accessToken, new CookieOptions
        {
            HttpOnly = true,
            Secure = true,
            SameSite = SameSiteMode.None,
            Expires = DateTimeOffset.UtcNow.AddMinutes(15)
        });
        
        cookies.Append("RefreshToken", refreshToken, new CookieOptions
        {
            HttpOnly = true,
            Secure = true,
            SameSite = SameSiteMode.None,
            Expires = DateTimeOffset.UtcNow.AddDays(7)
        });

//Cors
 public static IServiceCollection AddAppCors(this IServiceCollection services)
    {
        return services.AddCors(options =>
        {
            options.AddPolicy(CorsPolicies.Base, policy =>
            {
                policy.WithOrigins("https://localhost:3000")
                    .AllowCredentials()
                    .AllowAnyHeader()
                    .AllowAnyMethod();
            });
        });
    }

//Program.cs

...
builder.Services.AddAppCors(); //ADD MY CORS
...
var app = builder.Build();

app.UseHttpsRedirection();
app.UseRouting();
app.UseCors(CorsPolicies.Base); //USE MY CORS
app.UseAuthentication();
app.UseJwtSecurityStampValidation();
app.UseAuthorization();
app.MapControllers();

app.Run();