1.x and 2.x items not working together in same group

This is the first time I am using groups so I am not sure if this is an issue or I am missing something.

I am on OH2 and I used PaperUI to create a group item of switch type. If I create another switch item using PaperUI and add it to the group then I can toggle the switch by toggling the group item which I have added to the site map. This is the group definition from the file org.eclipse.smarthome.core.items.Item.json:

  "LivingRoomPower": {
    "class": "org.eclipse.smarthome.core.items.ManagedItemProvider$PersistedItem",
    "value": {
      "baseItemType": "Switch",
      "groupNames": [],
      "itemType": "Group",
      "tags": [],
      "label": "LivingRoomPower",
      "category": "Test",
      "functionName": "OR",
      "functionParams": [

I have another item which I have defined in panasonictv.items and not using PaperUI (this is because panasonictv does not have OH2 binding). If I add this item to a group using below syntax it is not affected when I toggle the group item. This is from panasonictv.items:

Switch LivingRoomTVPower "Power" (LivingRoomPower) {panasonictv="livingroom_panasonic_viera:POWER"}

In my sitemap file I have added the group switch:

Switch item=LivingRoomPower