Curl and Acymailing: some issues

Hello,
I am trying to setup a subscribe form for acymailing
using Chronoforms V5

here are my cURL action values

target url:

http://infinitemandala.com/index.php?

fields map:

ctrl="sub"
task="optin"
option="com_acymailing"
hiddenlists=1,2
subscription=subscription
user[email]=email

after testing the user is added to acymailing users, but not subscribed to any list
do you have any idea where the error could be?

test form here: http://infinitemandala.com/index.php?option=com_chronoforms5&chronoform=iscrizione-newsletter

Thank you