Hi Danny, thanks for posting! Sorry to hear of this behavior and I will be happy to help!
Thank you for the description of what you are seeing. Based off of this, would you be able to let us know the Display Settings that are in place after turning off the TV when Display 1 turns off and Display 2 ( attached to our adapter ) is the primary monitor? I am curious to see what Windows is automatically changing the Display Settings to when this behavior occurs as our adapter does not have the ability to control these settings. I suspect that a specific cached configuration is being loaded with settings that may need to be changed. If my theory is correct, we’d want to set Display 1 as the Primary display and then extend to the 2nd Display to make these changes.
If you are not sure how to check the Display Settings ( and assuming you are running Windows 10 ), you can right click in an open area on your Desktop and select “Display settings” from the menu. You should then see the Windows Display Settings application open where it will tell you the Multiple monitor settings that are set as well as which monitor is the main display (example screenshot below).
Please let us know if adjusting the Display Settings helps. If not, we’ll want to examine some log files to see if they can tell us what is happening. To help us do so please download and run our diagnostic utility PlugDebug --> http://plugable.com/support/plugdebug while our adapter is connected and Display 2 is set as the primary with Display 1 not active. Please send us the file that is created on your Desktop by attaching to and email to our direct support email at firstname.lastname@example.org with ‘Ticket Number 158117’ in the subject line so we can match everything up. We will examine the logs and determine next steps from there.