i've checked the LG website and found that after the webOS23 SW Update, the Screen Saver entry time has been increased from 3 minutes to 30 minutes. This might be the reason why you're not seeing the screensaver activate on the home page.
Can't believe this .This will only encourage screen damage Shocked !
You’ve reminded me I had to update something to update the YouTube app on our LG. All seems to have worked but I must check the screensaver. It was always very quick off the mark!