I will let others discuss the various options with the television itself.
I had exactly this issue with a different brand of smart television. Once it was turned on, I could control it with a voice assistant. But there was no way to turn it on through the standard integration.
If you are willing to spend about $40, there is a small IR blaster from switchbot that you can use. It has a smartthings integration, as well as an integration with Alexa and with Google Home. It is easy to setup and use. So one extra device, and the problem is solved.
I know not everyone will want to go this way, but it has worked very well for us.
Here’s my project report on it. (The topic title is a clickable link.)
