FTP Upload not working correctly

[uptownwings]

Hi guys.

I am running into the following issue.
Whenever I need to upload small files, everything is okay. Like 6k, 9k files, no problems there.
But when the files are bigger, a small portion is uploaded and then the upload just seems to die and timeout. I do not know what is going on. I tried several FTP locations that I know have different server software running, I tried different libraries to do this (Synapse and Codebot). Both with the exact -same- result.
It is just weird  and I can't figure out what is going on. What am I missing here?

I created a quick and dirty example program as follows:
The codebot library is here: https://github.com/sysrpl/Cross.Codebot

Code: Pascal  [Select][+][-]

1. unit Main;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   Classes,
9.   SysUtils,
10.   Forms,
11.   Controls,
12.   Graphics,
13.   Dialogs,
14.   ExtCtrls,
15.   StdCtrls,
16.   FileUtil,
17.   codebot.Networking.Ftp,
18.   codebot.System;
19.  
20. type
21.  
22.   { TForm1 }
23.  
24.   TForm1 = class(TForm)
25.     Button1: TButton;
26.     Memo1: TMemo;
27.     Panel1: TPanel;
28.     procedure Button1Click(Sender: TObject);
29.     procedure FormCreate(Sender: TObject);
30.   private
31.     FTPClient: TFtpClient;
32.     procedure Progress(Sender: TObject; const Size, Transmitted: LargeWord);
33.   public
34.  
35.   end;
36.  
37. var
38.   Form1: TForm1;
39.  
40. implementation
41.  
42. {$R *.lfm}
43.  
44. { TForm1 }
45.  
46. procedure TForm1.Button1Click(Sender: TObject);
47. var
48.   FileList: TStringList;
49.   i: Integer;
50. begin
51.   FileList := TStringList.Create;
52.   FindAllFiles(FileList,
53.     '/location/on/your/disk',
54.     '*', False);
55.   Memo1.Lines.Clear;
56.   Memo1.Lines.Add(FileList.Text);
57.  
58.   FTPClient.Connect;
59.   FTPClient.MakeDir('StorageFolder');
60.   FTPClient.ChangeDir('StorageFolder');
61.  
62.   for i := 0 to FileList.Count -1 do begin
63.     Memo1.Lines.Add('Uploading file ' + ExtractFileName(FileList[i]));
64.     FTPClient.FilePut(FileList[i], ExtractFileName(FileList[i]));
65.   end;
66.  
67.   FTPClient.Disconnect;
68. end;
69.  
70. procedure TForm1.FormCreate(Sender: TObject);
71. begin
72.   FTPClient := TFTPClient.Create;
73.   FTPClient.Host := 'hostname.domain.tld';
74.   FTPClient.UserName := 'username';
75.   FTPClient.Password := 'password';
76.   FTPClient.OnProgress:=@Progress;
77. end;
78.  
79. procedure TForm1.Progress(Sender: TObject; const Size, Transmitted: LargeWord);
80. begin
81.   Memo1.Lines.Add('Progress: ' + IntToStr(Transmitted) + '/' + IntToStr(Size));
82. end;
83.  
84. end.
85.                  
86.