Roku Express device purchased in the summer of 2024 powers off the TV and itself. It shuts off on its own within about 60 seconds after turning on the TV or device.
The TV sleep mode is not activated and is not the cause of the problem.
After conducting some tests by disconnecting the Roku device from the TV, the TV does not shut down on its own. The problem is not from the TV.
The problem started immediately after purchase, as soon as I first connected this device to the TV.
The Roku Express device was purchased at Best Buy at the Marché Central in Montreal, Quebec, Canada.