I have gone through the TV menus and turned eco things off as far as I can tell. Sleep timers are also off. Having said that, I may want to check the service menu of the LG unit, as it lists more details than what is visible in the user menus. The problem is that these service settings are not individually changeable, but they seem to be set by whatever Region/Country code you enter for the TV. I recently changed my Region code from EU to US, using the code listed in the Eclipse service manual, so it should be OK, However, this is what the problem started.
The reason I changed to US region was to be able to access the LG Store contents. I have now installed the YouTube TV app, which I am using for live TV), and I think this app is the reason that the LG unit sometimes freezes. Sound stops, picture freezes and the only way to recover is to pull the power cord. I am pretty sure I have seen the annoying auto-standby using other apps, so I will only blame the YouTube TV app for the LG freezing problem.