Need to change user account lifetime without resetting password
We've just configured SSL VPN on our TZ400. I have set up several users who have successfully connected via NetExtender from their PCs. Now I want to change their user info in the TZ400 to expire their passwords after some period of time.
I have found that whenever I go into Users -> Local Users & Groups, and modify a user, the password gets reset in the TZ400, even if modifying 'Groups' or 'VPN Access'. After making any change then clicking OK, I get a message that passwords do not match and have to set both the password and the confirm.
The users have all been required to change their passwords to something private which I do not know and I hate to make them change their passwords again just because I set a lifetime duration.
Is there any way around this?