jahutchi as you're clearly not a basic user, please do an experiment for me.
ssh onto your Kodi box. cd /storage/.kodi/addons/service.vpn.manager
Edit service.py
Line 565(ish...) has this:
current_name = xbmc.getInfoLabel("Container.FolderName")
straight after it add
window_id = xbmcgui.getCurrentWindowId()
newPrint("Window ID is " + str(window_id))
It's python, so you'll need to space out the indent (not tab) and line it up with the preceding line.
Reboot (this bit is necessary to pick up the change), wait for the VPN to connect then go to live TV. Then stop with the GUI check out the Kodi log via SSH (/storage/.kodi/temp/kodi.log). You should multiple messages that look like this :
22:53:56 T:10076 ERROR: Window ID is 10617
I need you to identify the number shown after you switch to live TV. My guess is that it'll be the last one you see, and maybe there will be multiple, like one every 10 seconds or so. What's the number at the end? You'll also see a bunch of other messages with different numbers (likely 10000) before it. You can ignore these.
Then back to the GUI and play around with Live TV, opening streams, going to records, whatever you do and then look at the log again. What other numbers do you see? I'm trying to establish if Live TV (and radio) always uses the 10600 - 10699 range.
If they are in the range I'm guessing, then go back to the service.py file.
Delete this line of the change you made above :
newPrint("Window ID is " + str(window_id))
and replace it with :
if window_id > 10600 and window_id < 10699: current_name = "Live TV"
Now reboot and try using your system. In my testing, I see this working fine, but I'm using the demo PVR and the simple PVR to test with, not TVheadend. If I use iVue, it doesn't work as it's not a PVR add-on and uses a custom window ID. Can you also do other stuff, like use other filtered add-ons that need a differnet VPN and check that the Live TV will always revert to your primary too please?
Let me know what you find out. If this works you can keep running with it for the time being.