The first time I lost signal a screen popped up. I don’t remember the exact wording but there was a box to check to make streaming the default with signal loss.
This is a very strange request for a new member. In the twenty years that I have been in this forum I don’t ever recall a question like this from a new member.
No it's not your thumb. I've been watching an OTA channel for 30 minutes. Press the back button some times it will go to the time I tuned that channel. Thirty minutes ten minutes whatever.