SIP issue at "sip-helper" under system settings

Hello!

I`m using Fortigate 60C with OS6.0 and got issue with SIP - I made everything from https://kb.fortinet.com/kb/documentLink.do?externalID=FD36405 but when I type set sip-helper disable (first of course i`m typing config system settings) it isn`t showing on system settings (show system settings), I got only:

config system settings set v4-ecmp-mode weight-based set sip-nat-trace disable set default-voip-alg-mode kernel-helper-based set gui-(...)

And I add set sip-helper disable plenty times but with no-show effect. Is this normal? How can I check if sip-helper is disabled or not?

Thanks in advance