Ftp backup not working

Hi,

im trying to setup automatic backup via ftp. but sophos lost connection with ftp server.

i can upload files from any computer behind the sophos.

this is the filezilla server log:

my sophos wan interface ip: 10.16.26.2

(000012)31/05/2019 22:57:52 - (not logged in) (10.16.26.2)> Connected on port 21, sending welcome message...
(000012)31/05/2019 22:57:52 - (not logged in) (10.16.26.2)> 220-FileZilla Server 0.9.60 beta
(000012)31/05/2019 22:57:52 - (not logged in) (10.16.26.2)> 220-written by Tim Kosse (tim.kosse@filezilla-project.org)
(000012)31/05/2019 22:57:52 - (not logged in) (10.16.26.2)> 220 Please visit https://filezilla-project.org/
(000012)31/05/2019 22:57:52 - (not logged in) (10.16.26.2)> USER tes
(000012)31/05/2019 22:57:52 - (not logged in) (10.16.26.2)> 331 Password required for tes
(000012)31/05/2019 22:57:52 - (not logged in) (10.16.26.2)> PASS ***
(000012)31/05/2019 22:57:52 - tes (10.16.26.2)> 230 Logged on
(000012)31/05/2019 22:57:52 - tes (10.16.26.2)> TYPE I
(000012)31/05/2019 22:57:52 - tes (10.16.26.2)> 200 Type set to I
(000012)31/05/2019 22:57:52 - tes (10.16.26.2)> EPSV
(000012)31/05/2019 22:57:52 - tes (10.16.26.2)> 229 Entering Extended Passive Mode (|||64425|)
(000012)31/05/2019 22:58:07 - tes (10.16.26.2)> disconnected.