lftp fails uploads with files over 14434 bytes.

[cloc3]

Using lftp on a gentoo box, I have problem to upload files large more than 14434 bytes.
for example:

lftp [[email protected]](mailto:[email protected])@ftp.cloc3.net:/www.cloc3.net/varie> put A.txt
14434 bytes transferred                         
lftp [[email protected]](mailto:[email protected])@ftp.cloc3.net:/www.cloc3.net/varie> ls A.txt
-rwxr-xr-x    1 188531235  188531235       14434 Feb 13 17:23 A.txt
lftp [[email protected]](mailto:[email protected])@ftp.cloc3.net:/www.cloc3.net/varie> put A.txt
14436 bytes transferred                         
lftp [[email protected]](mailto:[email protected])@ftp.cloc3.net:/www.cloc3.net/varie> ls A.txt
-rwxr-xr-x    1 188531235  188531235           0 Feb 13 17:23 A.txt

In the example, put command produces a correct log, but the file accessed with ls command has null size when 14436 are transfered.
uploading the same file with filezilla works well. so, I think the problem should be in the client.

[cloc3]

I add some more info.
lftp session:
open ftps://<username:password@servername

rc file:

set ssl:verify-certificate no
set xfer:clobber yes

example of a failed transfer for a 14436 byte long text file, in debug mode:

lftp [email protected]@ftp.cloc3.net:/www.cloc3.net/varie> debug 10
lftp [email protected]@ftp.cloc3.net:/www.cloc3.net/varie> put A.txt
copy-peer: EOF on FD 5
copy: get hit eof
copy: waiting for put confirmation
---> TYPE I
<--- 200 Type set to: Binary.                   
---> PASV
<--- 227 Entering passive mode (89,46,104,218,201,117).
---- Connessione del socket dei dati a (89.46.104.218) porta 51573
---- Data connection established                 
0:0 translated to pair 0:0 (0,0)
0 translated to pair 0:0 (0,0)
0:0 translated to pair 0:0 (0,0)
0 translated to pair 0:0 (0,0)
0:0 translated to pair 0:0 (0,0)
0 translated to pair 0:0 (0,0)
---> STOR A.txt
<--- 125 Data connection already open. Transfer starting.
WARNING: Certificate verification: subjectAltName does not match ‘ftp.cloc3.net’ (BD:C5:E8:0F:21:E2:82:C3:DA:04:31:8D:C2:0B:34:68:9F:8E:8E:35)
---- Chiusura del socket dati
<--- 226 Transfer complete.                                 
---> MFMT 20250213172346 A.txt
<--- 213 Modify=20250213172346; /www.cloc3.net/varie/A.txt. 
copy: put confirmed store
copy: get is finished - all done
14436 bytes transferred
lftp [email protected]@ftp.cloc3.net:/www.cloc3.net/varie> ls A.txt
---> TYPE A
<--- 200 Type set to: ASCII.                   
---> PASV
<--- 227 Entering passive mode (89,46,104,218,201,95).
---- Connessione del socket dei dati a (89.46.104.218) porta 51551
---- Data connection established               
0:0 translated to pair 0:0 (0,0)
0 translated to pair 0:0 (0,0)
0:0 translated to pair 0:0 (0,0)
0 translated to pair 0:0 (0,0)
0:0 translated to pair 0:0 (0,0)
0 translated to pair 0:0 (0,0)
---> LIST A.txt
<--- 150 File status okay. About to open data connection.
WARNING: Certificate verification: subjectAltName does not match ‘ftp.cloc3.net’ (BD:C5:E8:0F:21:E2:82:C3:DA:04:31:8D:C2:0B:34:68:9F:8E:8E:35)
<--- 226 Transfer complete.           
---- Got EOF on data connection
---- Chiusura del socket dati
-rwxr-xr-x    1 188531235  188531235           0 Feb 13 17:23 A.txt
copy: get hit eof
copy: waiting for put confirmation
copy: put confirmed store
copy: get is finished - all done

example of a successful transfer of a 14434 byte long text file, in debug mode:

lftp [email protected]@ftp.cloc3.net:/www.cloc3.net/varie> debug 10
lftp [email protected]@ftp.cloc3.net:/www.cloc3.net/varie> put A.txt
copy-peer: EOF on FD 5
copy: get hit eof
copy: waiting for put confirmation
---> TYPE I
<--- 200 Type set to: Binary.                   
---> PASV
<--- 227 Entering passive mode (89,46,104,211,200,118).
---- Connessione del socket dei dati a (89.46.104.211) porta 51318
---- Data connection established                 
0:0 translated to pair 0:0 (0,0)
0 translated to pair 0:0 (0,0)
0:0 translated to pair 0:0 (0,0)
0 translated to pair 0:0 (0,0)
0:0 translated to pair 0:0 (0,0)
0 translated to pair 0:0 (0,0)
---> STOR A.txt
<--- 150 File status okay. About to open data connection.
WARNING: Certificate verification: subjectAltName does not match ‘ftp.cloc3.net’ (BD:C5:E8:0F:21:E2:82:C3:DA:04:31:8D:C2:0B:34:68:9F:8E:8E:35)
---- Chiusura del socket dati
<--- 226 Transfer complete.                                 
---> MFMT 20250215093952 A.txt
<--- 213 Modify=20250215093952; /www.cloc3.net/varie/A.txt. 
copy: put confirmed store
copy: get is finished - all done
14434 bytes transferred
lftp [email protected]@ftp.cloc3.net:/www.cloc3.net/varie> ls A.txt
---> TYPE A
<--- 200 Type set to: ASCII.                   
---> PASV
<--- 227 Entering passive mode (89,46,104,211,200,236).
---- Connessione del socket dei dati a (89.46.104.211) porta 51436
---- Data connection established               
0:0 translated to pair 0:0 (0,0)
0 translated to pair 0:0 (0,0)
0:0 translated to pair 0:0 (0,0)
0 translated to pair 0:0 (0,0)
0:0 translated to pair 0:0 (0,0)
0 translated to pair 0:0 (0,0)
---> LIST A.txt
<--- 150 File status okay. About to open data connection.
WARNING: Certificate verification: subjectAltName does not match ‘ftp.cloc3.net’ (BD:C5:E8:0F:21:E2:82:C3:DA:04:31:8D:C2:0B:34:68:9F:8E:8E:35)
---- Got EOF on data connection       
---- Chiusura del socket dati
<--- 226 Transfer complete.
-rwxr-xr-x    1 188531235  188531235       14434 Feb 15 09:39 A.txt
copy: get hit eof
copy: waiting for put confirmation
copy: put confirmed store
copy: get is finished - all done