Unhandled Exception on iOS Devices due to HttpClient [Xamarin.Forms (Mobile Blazor Bindings)]

Hello

I've made an hybrid mobile application using Mobile Blazor Bindings (which is based on Xamarin Forms). It's on production but since the it's deployed I'm having a problem with iOS platform.

At first problems arose on login procedure

public async Task Login(LoginRequest loginRequest)
{
       var result = await _httpClient.PostAsJsonAsync("api/auth/login", loginRequest);
      if (result.StatusCode == System.Net.HttpStatusCode.BadRequest) throw new Exception(await result.Content.ReadAsStringAsync());
      result.EnsureSuccessStatusCode();
}

This code snippet is the method called by AuthService on client side. Throwing an exception resulted "Unhandled Exception" on -some- iOS Devices. I haven't been able to reproduce the same error on both iPhoneSimulator (iOS 14.4) and my iPhone 5S (iOS 12.5.1)

So to "kinda" fix it I change the method a little bit:

 public async Task<HttpResponseMessage> Login(LoginRequest loginRequest)
{
    var result = await _httpClient.PostAsJsonAsync("api/auth/Login", loginRequest);
    if (result.IsSuccessStatusCode)
    {
        return result;  //result.EnsureSuccessStatusCode();
    }
    return new HttpResponseMessage() { StatusCode = System.Net.HttpStatusCode.BadRequest };
}

I also had the same problem with EnsureSuccessStatusCode so I deleted it too.

And this is the State Provider which calls this method:

public async Task<int> Login(LoginRequest loginParameters)
{
    var result = await api.Login(loginParameters);
    if (result.StatusCode == System.Net.HttpStatusCode.OK)
    {
         NotifyAuthenticationStateChanged(GetAuthenticationStateAsync());
        return 0;
    }

    NotifyAuthenticationStateChanged(GetAuthenticationStateAsync());
    return 1;
}

This solved my problem at login page but now I can't login due to another "Unhandled Exception" which says "Unhandled Exception", Response Status code does not indicate success: 404 (Not Found).

How is this possible? I can access to my API on all clients but only on some iOS devices it can't handle the API Requests.

A friend of my suggested to me that maybe the way I define my HttpClient causing the problem.

public static HttpClient _http = new HttpClient() { BaseAddress = new Uri("http://api.xxxxx.com") };

This is how I defined it. Does it matter if it was new Uri("http://api.xxxxx.com") or new Uri("http://api.xxxxx.com/") or when I 'm calling the PostAsJsonAsync for example should it be like this _httpClient.PostAsJsonAsync("api/auth/Login", loginRequest); or this _httpClient.PostAsJsonAsync("/api/auth/Login", loginRequest); which one is the right way if that even matters?