Forum Discussion
The phone number you called is NOT Roku support. They don't offer any telephone support. So I don't know who you were talking to. They were probably trying to find a way to charge you a fee for something you didn't really need. But I just searched for that number and discovered it's a Sharp support line. Sharp does sell Roku TVs, but that number was not Roku.
I can't explain what problem you're encountering getting your TV working again for OTA broadcasts. The TV does not require Internet access to watch OTA, although an Internet connection is required to initially set the TV up after a factory reset. The TV must be linked to your Roku user account, which requires an Internet connection to complete. After that you shouldn't need a connection ever.
I'm not certain, but the "Live TV" link might be trying to take you to online channels, not what you receive from an antenna. I don't have a Roku TV close by me at the moment, so can't look at the menu structure. Best I can remember is a home screen tile labeled "Antenna", but with the Roku OS updates they might have changed that.