I get a "Roku Tech Tips Banner" which pops up every every 5 seconds along the left side of the screen, the TV is a Westinghouse 40" model WR40FX2019. I checked all the settings to turn this annoying feature off without any success. I press any button on the remote to make go away, but it comes back in 5 seconds. Please advise.
These things are just special purpose computers, and just like their big brothers, sometimes operational problems cans be solved by a system restart.
From the Roku home screen use menu path Settings > System > System restart. (On a Roku TV the menu path is Settings > System > Power > System restart.)
Since it's a TV, see if there's a store demo mode that is turned on. TVs with such a mode will often toss banners on the screen like that.