Switch Item on sitemap does not affect item state?

EDIT: I have come across the link: http://localhost:8080/classicui/app?sitemap=knx_sitemap . This sitemap switch worked. I’m not sure if there is a similar url for PaperUI or it only accepts things, help to configure these would still be appreciated. The UI issue described below must be a bug with HABmin.

I am using OH2 via Docker image, I have HUE, Sonos and Z-Wave bindings installed and working fine. I have installed KNX through Paper UI as well but it does not seem to be as well supported, I’ve been learning about the various configuration files but still cannot seem to get the UI part to work.

/openhab/conf/items/knx.items:
Switch knx_desk_light "Ceiling Lamp" { knx="<0/0/3" }

/openhab/conf/sitemaps/knx_sitemap.sitemap:

sitemap knx_sitemap label="KNX Sitemap"
{
    Frame {
        Switch item=knx_desk_light label="Desk Lights" mappings=[1="ON", 0="OFF"]
    }
}

Using cURL as follows works:
curl --header "Content-Type: text/plain" --request PUT --data "ON" http://localhost:8080/rest/items/knx_desk_light/state

When viewing sitemap UI in HABmin2(not clear how to view on other UIs), I have my switch and toggling it on/off does not seem to affect the KNX address. When I trigger it via a physical switch openHABs log picks up on it, so communication read/write seems to be fine, just the UI is not updated and does not trigger a state change to the group address?

I have tried to follow docs and what others have said in github issues and community forum posts but I seem to be missing something. Do I need to create a .things file? I could not find docs on structure/format and channels that I’ve read others mention. Is there a way to export the default sitemap openHAB produces to config files like I’ve been creating? Then I could reference it.

If it helps here is some log information:
/openhab/userdata/logs/events.log

2016-06-20 08:29:51.290 [ItemCommandEvent          ] - Item 'knx_desk_light' received command OFF
2016-06-20 08:29:51.336 [ItemStateChangedEvent     ] - knx_desk_light changed from NULL to OFF
2016-06-20 08:29:51.436 [ItemCommandEvent          ] - Item 'knx_desk_light' received command OFF
2016-06-20 08:30:15.086 [ItemCommandEvent          ] - Item 'knx_desk_light' received command ON
2016-06-20 08:30:15.136 [ItemStateChangedEvent     ] - knx_desk_light changed from OFF to ON
2016-06-20 08:30:15.187 [ItemCommandEvent          ] - Item 'knx_desk_light' received command ON

/openhab/userdata/logs/openhab.log:

2016-06-20 08:30:15.085 [DEBUG] [.binding.knx.internal.bus.KNXBinding] - Received groupWrite Event.
2016-06-20 08:30:15.086 [INFO ] [smarthome.event.ItemCommandEvent    ] - Item 'knx_desk_light' received command ON
2016-06-20 08:30:15.089 [DEBUG] [.binding.knx.internal.bus.KNXBinding] - Received update (item='knx_desk_light', state='ON')
2016-06-20 08:30:15.135 [DEBUG] [.binding.knx.internal.bus.KNXBinding] - Wrote value 'ON' to datapoint 'command DP 0/0/3 knx_desk_light, DPT main 0 id 1.001, low priority'
2016-06-20 08:30:15.136 [INFO ] [marthome.event.ItemStateChangedEvent] - knx_desk_light changed from OFF to ON
2016-06-20 08:30:15.184 [DEBUG] [.binding.knx.internal.bus.KNXBinding] - Received groupWrite Event.
2016-06-20 08:30:15.186 [DEBUG] [.binding.knx.internal.bus.KNXBinding] - Received update (item='knx_desk_light', state='ON')
2016-06-20 08:30:15.187 [INFO ] [smarthome.event.ItemCommandEvent    ] - Item 'knx_desk_light' received command ON
2016-06-20 08:30:15.235 [DEBUG] [.binding.knx.internal.bus.KNXBinding] - Wrote value 'ON' to datapoint 'command DP 0/0/3 knx_desk_light, DPT main 0 id 1.001, low priority'