Finally! I could connect after 5 months of trying every now and then.. you can see the log of my attempts in this thread Hence the first thing I am doing on connecting successfully is to write about it here
Two things helped made it work -
Step 1: Update Windows 10 to the latest version - version 1803, build 17134.48
If you have not received this update yet (in my case, it was downloaded automatically but failed to instal several times) go to the Windows update center online, download and install the update manually.
This alone did not suffice for me, what happened was that the LG TV would get connected for a few seconds and then get disconnected again.
Step 2: So, what worked for me is that I happened to disconnect the TV from the internet connection but leave the WiFi radio 'ON' in the TV. Your laptop could stay connected to the internet, does not matter but the TV shouldn't (perhaps it can handle a connection to just one device at a time!!). Go to Screen share on the TV and try connecting from the 'Connect' option in the Windows 10 notification menu of the taskbar and that should be it!