I tried every solution mentioned except one, removing the back and straightening/flattening the wifi module cables because I have a 65" model and would have to handle it myself. Well I bit the bullet and got it down and after flattening the cables I have not had the notification in the past 11 days.
This appears to have fixed it and also fixed the issue of the wifi being off and no way to turn it on. Wifi is working now like it always has. I have had this TV for more than 2 1/2 years.
So if you haven't tried this, give it a try. Hope this helps.