For All of those People having problems with the Live TV App not keeping the local over-the-air channels scanned on the App or in the Live TV App. I'm pretty sure I've found & fixed the issue. Here is what you need to do. 1st Go to Settings> TV Input> Manage Channels> Hide Streaming Channels. 2nd Go to Settings> TV Input> Live TV> Rename> Antenna TV. 3rd Go to Settings> TV Input> Antenna> Scan for Channels> Start Over> OK. Finally Go to Settings> System> Power> Power on Antenna TV>.
AT THIS POINT I POWERED OFF THE ROKU TV WAITED A FEW SECONDS AND POWERED IT BACK ON. WHEN I DID THE TELEVISION WENT STRAIGHT TO ANTENNA TV INSTEAD OF THE HOME SCREEN AND ALL THE OVER-THE-AIR CHANNELS I HAD SCANNED PREVIOUSLY WERE THERE AND WORKING ON THE LIVE TV GUIDE AS WELL.
HOPE THIS HELPS EVERYONE WHO WAS HAVING THE SAME ISSUE I WAS AND I DIDN'T EVEN NEED ROKU SUPPORT BECAUSE WHEN I TRIED GETTING HELP FROM THEM WITH THE ISSUE THEY WANTED ME TO GO IN AND DO A SYSTEM UPDATE. THIS WAS MUCH EASIER, MORE EFFECTIVE, & FASTER..