The firewall setup step in tl-setup bugs out if you go back to it in tl-setup after finishing it. The expected behaviour is that you just see the "The local firewall has been configured..." message and can't restart it.
Seen on 4.14.0, and 4.14.0post.
I've seen two behaviours:
* I go back to the initial firewall page, with the check box to enable/disable configuration
* I get the "has been configured" message, but it still reconfigures the firewall a second time