FortiClient VPN "Save Password" option.

Hello everyone! I'm looking for a way to make FortiClient (the free one, VPN only) save user password. When I fresh install FortiClient VPN (7.4.3 hotfix 1.8758), this checkbox is not present at all. I've read some manuals on XML configs and found configuration parameters that make this checkbox visible. I craft a .conf file with the parameters, import it, the checkbox I wanted is present, but once my connection is establishsed, the utility goes to tray, and then I untray it back (a lock sign in the top right corner is present even if I turned it off before), I break the connection I've just established, and all the checkboxes are gone from GUI.

What am I doing wrong and how to fix it? It's just really frustrating to re-enter my password everytime. Any help is appreciated. Thanks in advance!