reproducible on neon dev unstable connect to a wireless network click wireless icon in system tray uncheck wireless checkbox on top (now your connection is offline) check the same checkbox your wi-fi is online again but the checkbox remains unchecked
Bug persists in plasma 5.13.4, see the screencast recorded on neon dev unstable. I click the checkbox on top, my wi-fi adapter is disabled and no wi-fi network is available anymore, as expected. When I click the checkbox again, the wi-fi adapter is re-enabled and all wi-fi connections are listed, as expected. However the checkbox remains unchecked.
Created attachment 114275 [details] demonstration
I still cannot reproduce this. Can you run "dbus-monitor --system" in a terminal and reproduce the issue and then attach here output from there?
Created attachment 114324 [details] dbus-monitor
Did you enable wireless after you disabled it? In the log I see twice it has been disabled, but not enabled. Either you didn't enable it or NM doesn't correctly propagate this change which would explain your problem.
I followed exactly the same steps shown in my screencast.
What is your NetworkManager version? I think that the problem is in NetworkManager given the information it sends us over DBus.
network manager 1.2.6-0ubuntu0.16.04.2 on neon dev unstable.
Ok, a bit old NM version. I would suggest try with latest one and report this bug to NM if you verify it's still reproducible.
Bug is reproducible on OpenSuse krypton running network manager 1.10.10-2.1.
Created attachment 114377 [details] dbus-monitor OpenSuse krypton
Same situation, all we get from NM is that wireless is disabled. Report your issue to NetworkManager please.