ConfigureAwait(false) not giving response and app get stuck

Question

I am using refit in my xamarin.forms project to connect to the server and download some data. The code below works properly if server is online but when server is offline, I got stuck and I am not getting response from the ConfigureAwait(false) function.

public async Task<bool> download()
{
    var apiService = NetworkService.GetApiService();
    try 
    {
        var data = await apiService.getInitialData().ConfigureAwait(false);
        insertData(fullPath, data);
        return true;    
    }
    catch (ValidationApiException e) 
    {
        return false;
    }
    catch (ApiException e) 
    {
        return false;
    }
    ...